Co-reporter:Jingrun Zhu, Xiaoling Yang, Yihua Zhu, Yuanwei Wang, Jin Cai, Jianhua Shen, Luyi Sun, and Chunzhong Li
The Journal of Physical Chemistry Letters September 7, 2017 Volume 8(Issue 17) pp:4167-4167
Publication Date(Web):August 18, 2017
DOI:10.1021/acs.jpclett.7b01820
Here we report the room-temperature, atmospheric synthesis of Mn-doped cesium lead halide (CsPbX3) perovskite quantum dots (QDs). The synthesis is performed without any sort of protection, and the dual-color emission mechanism is revealed by density functional theory. The Mn concentration reaches a maximum atomic percentage of 37.73 at%, which is significantly higher in comparison to those achieved in earlier reports via high temperature hot injection method. The optical properties of as-prepared nanocrystals (NCs) remain consistent even after several months. Therefore, red-orange LEDs were fabricated by coating the composite of PS and as-prepared QDs onto ultraviolet LED chips. Additionally, the present approach may open up new methods for doping other ions in CsPbX3 QDs under room temperature, the capability of which is essential for applications such as memristors and other devices.
Co-reporter:Yunfeng Li;Jianhua Shen;Yanjie Hu;Zhuo Sun;Guoquan Min;Shengjie Qiu;Zhitang Song;Chunzhong Li
Industrial & Engineering Chemistry Research October 14, 2015 Volume 54(Issue 40) pp:9750-9757
Publication Date(Web):Publication Date (Web): September 29, 2015
DOI:10.1021/acs.iecr.5b02090
Unique chainlike MFe2O4 (M = Cu, Ni, Co, and Zn) nanoaggregates (NAs) have been prepared by facile flame spray pyrolysis of nitrates/ethanol precursor. Synthesized MFe2O4 are composed of primary nanocrystallites mainly ranging from 8 to 20 nm and show uniform aggregations with size of 200–400 nm. As heterogeneous catalysts, it is clearly noted that CuFe2O4 NAs have the highest catalytic activity for the reduction of nitroaromatic compounds compared to NiFe2O4, CoFe2O4, and ZnFe2O4. The highest rate constant of 36.17 min–1·g–1 is achieved at a low catalyst usage (10 μL, 0.2 mg·mL–1). The remarkably enhanced catalytic performance of CuFe2O4 NAs is mainly attributed to the promoted electron transfer on Cu2+ active sites, which is facilitated by unique spinel structures and chainlike aggregate morphology. It is demonstrated that flame spray pyrolysis technique is an effective route to produce binary or complex oxides for potential industrial use.
Co-reporter:Guiqi Jia;Yao Fu;Qilin Cheng;Chunzhong Li;Yanjie Hu;Hao Jiang
Industrial & Engineering Chemistry Research March 25, 2015 Volume 54(Issue 11) pp:2960-2965
Publication Date(Web):2017-2-22
DOI:10.1021/acs.iecr.5b00132
Compared to other transition metal oxides, V2O3 with a higher conductivity has attracted intense attention in energy storage fields. To further improve its rate capability and cycling stability, we demonstrate the synthesis of carbon-encapsulated ultrafine V2O3 nanowires (V2O3@C NWs) hybrids. The optimized V2O3@C NWs hybrids, when applied as anode materials for lithium-ion batteries (LIBs), deliver a high specific capacity of 985 mA h g–1 at 100 mA g–1, which is higher than V2O3 nanoparticles (V2O3 NPs, 248 mA h g–1) and even 2.6 times higher than graphite anodes. More significantly, they also exhibit remarkably enhanced rate capability (519 mA h g–1 at 5000 mA g–1) and long cycle life (860 mA h g–1 at 1000 mA g–1 after 300 cycles). Such fascinating electrochemical performance is mainly attributed to the uniform coating of carbon and their ultrafine nanostructure, which can further improve the conductivity and enrich the electrochemical active sites.
Co-reporter:Pengfei Liu;Yanjie Hu;Xiaoyu Hou;Yunfeng Li;Chunzhong Li
Industrial & Engineering Chemistry Research July 8, 2015 Volume 54(Issue 26) pp:6692-6697
Publication Date(Web):Publication Date (Web): June 19, 2015
DOI:10.1021/acs.iecr.5b00858
In this work, the novel macro-mesoporous TiO2 microspheres (MMTMs) have been synthesized via a spray drying route with fumed silica (FS) as template, followed by calcination and etching. The as-synthesized MMTMs have unique bimodal porous structures of macropores origin from FS template and mesopores accumulated by TiO2 nanoparticles. The macro-mesoporous structure endows the TiO2 microspheres with better surface area and wonderful light scattering property. When MMTMs are employed as the photoelectrodes of dye-sensitized solar cells, short-circuit current and open-circuit voltage are both improved and the high power conversion efficiency of 8.68% is obtained eventually, which is much higher than P25 photoelectrode. The excellent performance can be attributed to the excellent light-scattering property, better diffusion of electrolyte as well as superior electron transport owing to the unique bimodal pore structure and the dense packed of the internal nanoparticles of MMTMs.
Co-reporter:Shunan Zhao;Jianfei Huang;Yanyan Liu;Jianhua Shen;Hao Wang;Xiaoling Yang;Yihua Zhu;Chunzhong Li
Journal of Materials Chemistry A 2017 vol. 5(Issue 8) pp:4207-4214
Publication Date(Web):2017/02/21
DOI:10.1039/C6TA10749D
In this study, excellent full water splitting achieved with a rationally structured multimetallic Ni–Mo/Cu nanowire free-standing electrode prepared via scalable electrochemistry is reported. By combining a conductive nanostructured scaffold and highly active outer layers, the as-prepared Ni–Mo/Cu nanowires deliver superior hydrogen and oxygen evolution performance. To achieve a 20 mA cm−2 catalytic current in a 1 M KOH electrolyte, the NM-CNW requires an overpotential of only 152 mV for hydrogen evolution and 280 mV for oxygen evolution. When assembled into a full electrolyzer, the Ni–Mo/Cu nanowires can drive full water splitting at nearly 100% faradaic efficiency steadily up to 12 h without any significant performance decay, and afford a catalytic current close to that of the state-of-the-art Pt–RuO2 system over long-term operation.
Co-reporter:Hao Wang;Jianhua Shen;Jianfei Huang;Tengjing Xu;Jingrun Zhu;Yihua Zhu;Chunzhong Li
Nanoscale (2009-Present) 2017 vol. 9(Issue 43) pp:16817-16825
Publication Date(Web):2017/11/09
DOI:10.1039/C7NR06665A
CO oxidation is a typical heterogeneous catalytic reaction. Development of active and stable low-temperature CO oxidation catalysts has been one of the hot topics in the field of catalysis. In this work, we explored the catalytic application of a series of Au catalysts supported on CeO2 foam using a modified deposition–precipitation method for CO oxidation. Among them, the catalyst with 1.1% Au loading content showed the highest catalytic activity, leading to the CO total conversion at 20 °C. Based on the strategy of stepwise reduction of Au loading content, we finally obtained the atomically monodisperse Au/CeO2 catalyst with high stability and strong resistance to elevated temperature, on which in situ DRIFTS analysis and DFT study were further performed to study the possible reactive site. Our results implied that the Au atoms on the CeO2 foam are the more stable sites for CO adsorption on the catalysts.
Co-reporter:Kun Ma, Xue Liu, Qilin Cheng, Petr Saha, Hao Jiang, Chunzhong Li
Journal of Power Sources 2017 Volume 357(Volume 357) pp:
Publication Date(Web):31 July 2017
DOI:10.1016/j.jpowsour.2017.04.105
•Hierarchical V2O5 nanosheets are firmly grown on surface-decorated carbon cloth.•The polydopamine plays a pivotal role in the formation of robust flexible cathode.•The flexible cathode exhibits superior mechanical strength and LIBs performances.The search for an appropriate flexible cathode is pivotal to expediting the development of flexible and foldable lithium-ion batteries (LIBs). Herein, we demonstrate a simple and scalable synthesis of hierarchical V2O5 nanosheet arrays on polydopamine (PDA)-decorated carbon cloth with strong combination between them, which then directly applied as flexible cathode for LIBs. We found this flexible cathode with a loading mass of 2.1 mg cm−2 can deliver a high specific capacity of 120 mAh g−1 even at 15C (1C = 300 mA g−1) and maintain a long-term cycling stability, i.e. simply 0.30% capacity loss per cycle at 2C for 100 cycles without morphology change. More importantly, the corresponding areal capacity can reach as high as 560 μAh cm−2 at 210 μA cm−2, favorably comparing with the-state-of-art flexible cathode reported to date. Additionally, a flexible LIBs full cell has been assembled, exhibiting high mechanical strength and superior electrochemical performances.Download high-res image (202KB)Download full-size image
Co-reporter:Ling Chen;Hao Jiang;Haibo Jiang;Haoxuan Zhang;Shaojun Guo;Yanjie Hu;Chunzhong Li
Advanced Energy Materials 2017 Volume 7(Issue 15) pp:
Publication Date(Web):2017/08/01
DOI:10.1002/aenm.201602782
Constructing 3D hierarchical architecture consisting of 2D hybrid nanosheets is very critical to achieve uppermost and stable electrochemical performance for both lithium-ion batteries (LIBs) and hydrogen evolution reaction (HER). Herein, a simple synthesis of uniform 3D microspheres assembled from carbon nanosheets with the incorporated MoO2 nanoclusters is demonstrated. The MoO2 nanoclusters can be readily converted into the molybdenum carbide (Mo2C) nanocrystals by using high temperature treatment. Such assembling architecture is highly particular for preventing Mo-based ultrasmall nanoparticles from coalescing or oxidizing and endowing them with rapid electron transfer. Consequently, the MoO2/C hybrids as LIB anode materials deliver a specific capacity of 625 mA h g−1 at 1600 mA g−1 even after 1000 cycles, which is among the best reported values for MoO2-based electrode materials. Moreover, the Mo2C/C hybrids also exhibit excellent electrocatalytic activity for HER with small overpotential and robust durability in both acid and alkaline media. The present work highlights the importance of designing 3D structure and controlling ultrasmall Mo-based nanoparticles for enhancing electrochemical energy conversion and storage applications.
Co-reporter:Yuanwei Wang;Yihua Zhu;Xiaoling Yang;Jianhua Shen;Jingrun Zhu;Shaohong Qian;Chunzhong Li
Chinese Journal of Chemistry 2017 Volume 35(Issue 6) pp:949-956
Publication Date(Web):2017/06/01
DOI:10.1002/cjoc.201600771
AbstractSingle-crystal-like TiO2 mesoporous microspheres have been reported with high photocatalytic activity under ultraviolet light (UV light) because of their high specific surface areas and single-crystal-like channel walls. In this work, plasmonic gold nanoparticles (Au NPs) and β-NaYF4: Yb3+, Er3+ upconversion nanoparticles (UCNPs) were composited with single-crystal-like TiO2 mesoporous microspheres through a series of facile approaches, aiming at broadening response region of solar light from UV to visible and near infrared light and enhancing the photocatalytic activity further. The structure was rationally designed by modifying the pore size of TiO2 mesoporous microspheres so as to anchor plasmonic Au NPs, and covering β-NaYF4: Yb3+, Er3+ with SiO2 in order to embed UCNPs into TiO2 mesoporous microspheres via hydrophilic interaction. This work studied the attribution of Au NPs and UCNPs to photocatalysis and found out that combining Au NPs and certain amount of UCNPs with single-crystal- like TiO2 mesoporous microspheres in a monolithic architecture would bring enhanced broadband photocatalytic activity under simulated solar light. Consequently, the composite photocatalyts containing 150 mg UCNPs showed a significant enhancement in reaction rate, which was 36.02% higher than commercial P25 and 85.09% higher than pure TiO2 mesoporous microspheres under simulated solar light.
Co-reporter:Yu Hang Li, Yun Wang, Li Rong Zheng, Hui Jun Zhao, Hua Gui Yang, Chunzhong Li
Applied Catalysis B: Environmental 2017 Volume 209(Volume 209) pp:
Publication Date(Web):15 July 2017
DOI:10.1016/j.apcatb.2017.03.001
•Water-soluble Na2MoO4 salt demonstrates its capacity for photocatalytic overall water splitting.•Water-soluble inorganics has the capacity for photocatalytic overall water splitting.•Water-soluble Na2MoO4 can act as a new type of photocatalyst for overall water splitting.•Water-soluble semiconductors may have great potential to be applied in numerous important applications such as catalysis, photovoltaics, light emitting diodes and artificial photosynthesis.In the past 45 years, the search for semiconductors as active photocatalysts for overall water splitting has focused on insoluble materials and their hybrids. An important question is whether soluble semiconductors have the capacity for photocatalysis or similar applications. The dissolved semiconductors will lose the energy band structures for light absorption; however, the undissolved part in saturated solution can still generate electrons and holes under illumination. Unfortunately, this possibility has never been realized. Here we clearly demonstrate the use of a water-soluble sodium molybdate salt as an effective photocatalyst. The material can photocatalyze simultaneously the oxidation and reduction of water under band-gap irradiation. We anticipate that, as a large and traditional class of chemical compounds, the soluble semiconductors may have great potential to be applied in numerous important applications such as catalysis, photovoltaics, light emitting diodes and artificial photosynthesis.Download high-res image (127KB)Download full-size image
Co-reporter:Haiyan Wang, Hao Jiang, Yanjie Hu, Petr Saha, Qilin Cheng, Chunzhong Li
Chemical Engineering Science 2017 Volume 174(Volume 174) pp:
Publication Date(Web):31 December 2017
DOI:10.1016/j.ces.2017.09.007
•The carbon cloths are modified by micro-area etching and functionalization.•The maximal 2D heterointerface greatly improves sodium storage capacity.•The enlarged interlayer space of 0.99 nm enhances the diffusion kinetics of Na+.•An ultrastable capacity retention is achieved for over 10000 cycles.Development of ultra-stable high capacity electrodes is imperative for the widespread commercialization of sodium-ion batteries. Herein, we employed a micro-area etching and surface functionalization strategy to synthesize two-dimensional (2D) MoS2/C nanosheets with a well-defined heterointerface vertically anchored on a carbon cloth. The large MoS2/C nanosheet heterointerface and a high interlayer distance (0.99 nm) not only facilitated Na+ intercalation but also improved the diffusion kinetics of Na+ in the 2D interlayer space. A modulation of the cut-off voltage yielded a high specific capacity of 433 mAh g−1 at 0.2 A g−1 and 232 mAh g−1 at 10 A g−1 within the potential range of 0.4–3.0 V. These values are much higher than that of pure MoS2 nanosheet arrays (162 mAh g−1 at 10 A g−1). More importantly, during the first 1500 cycles, the capacity was maintained at ∼320 mAh g−1 at 1 A g−1, while after 10000 cycles, it became approximately ∼271 mAh g−1 at 3 A g−1. These are the best values ever reported for MoS2-based anode materials for SIBs. Furthermore, after being assembled into a flexible battery, it withstand repeated bending for over 200 times without any obvious capacity loss. Hence, this material is a promising electrode for future flexible batteries.Download high-res image (99KB)Download full-size image
Co-reporter:Haoxuan Zhang, Haibo Jiang, Yanjie Hu, Hao Jiang, Chunzhong Li
Green Energy & Environment 2017 Volume 2, Issue 2(Volume 2, Issue 2) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.gee.2016.12.004
Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems. Here, we present the synthesis of integrated Ni-P-S nanosheets array including Ni2P and NiS on nickel foam by a simple simultaneous phosphorization and sulfurization strategy. The resultant sample with optimal composition exhibits superior electrocatalytic performance for hydrogen evolution reaction (HER) in a wide pH range. In alkaline media, it can generate current densities of 10, 20 and 100 mA cm−2 at low overpotentials of only −101.9, −142.0 and −207.8 mV with robust durability. It still exhibits high electrocatalytic activities even in acid or neutral media. Such superior electrocatalytic performances can be mainly attributed to the synergistic enhancement of the hybrid Ni-P-S nanosheets array with integration microstructure. The kind of catalyst gives a new insight on achieving efficient and robust hydrogen generation.The integrated Ni-P-S nanosheets array has been demonstrated by a simple simultaneous phosphorization and sulfurization strategy, exhibiting superior electrocatalytic performances for hydrogen evolution reaction in a wide pH range.Download high-res image (229KB)Download full-size image
Co-reporter:Haiyan Wang;Hao Jiang;Yanjie Hu;Neng Li;Xiujian Zhao;Chunzhong Li
Journal of Materials Chemistry A 2017 vol. 5(Issue 11) pp:5383-5389
Publication Date(Web):2017/03/14
DOI:10.1039/C7TA00030H
The exploitation of high-capacity and long-life MoS2-based materials is highly important for developing lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Herein, we demonstrate the confined synthesis of 2D MoS2/polyaniline (MoS2/PANI) nanosheet heterostructures with well-defined interfaces, in which the interlayer distance of MoS2 is greatly enlarged from 0.62 nm to 1.08 nm. The introduction of such a big interlayer distance for efficient Li+/Na+ storage has never been demonstrated before. The unique MoS2/PANI nanosheets can address well the key challenges of traditional MoS2 anode materials related to low conductivity particularly in the vertical direction, easy restacking/aggregation, large volumetric change and sluggish Li+/Na+ diffusion kinetics in the interlamination. Consequently, they deliver a high reversible capacity, superior rate capability and long cycle life for both LIBs and SIBs. A state-of-the-art ab initio molecular dynamics (AIMD) simulation also reveals that MoS2/PANI nanosheets with enlarged interlayer spacing possess a remarkably improved Li+/Na+ diffusion mobility compared to pristine MoS2 nanosheets. The present material design concept opens new directions for finding efficient LIBs/SIBs anodes with high capacity, rate capability and stability.
Co-reporter:Yu Hang Li;Chunzhong Li;Hua Gui Yang
Journal of Materials Chemistry A 2017 vol. 5(Issue 39) pp:20631-20634
Publication Date(Web):2017/10/10
DOI:10.1039/C7TA07440A
Here, for the first time, we detect reversible structural changes of platinum oxide as an active site in photocatalytic water splitting by operando X-ray absorption fine structure spectroscopy. The platinum–oxygen bond length increases from 2.07 to 2.13 Å and the coordination number reduces from 4.0 to 2.5 between the ex situ and operating photocatalysts.
Co-reporter:Yuanwei Wang;Yihua Zhu;Jianfei Huang;Jin Cai;Jingrun Zhu;Xiaoling Yang;Jianhua Shen;Chunzhong Li
Nanoscale Horizons (2016-Present) 2017 vol. 2(Issue 4) pp:225-232
Publication Date(Web):2017/06/26
DOI:10.1039/C7NH00057J
CsPbBr3 perovskite quantum dots (CPBQDs) have exhibited excellent optical properties, which implies their potential as an appealing candidate for fluorescence resonance energy transfer (FRET) based detection. In this work, in order to enhance the subsurface concentration of CPBQDs, which is important for the efficiency of FRET detection, a nanoscale polymethyl methacrylate (PMMA) fiber membrane (d ≈ 400 nm) encapsulated with CPBQDs (CPBQDs/PMMA FM) is fabricated using an electrospinning method. The CPBQD/PMMA FM possesses comparable optical properties to CPBQDs, high quantum yields (88%) and a narrow half-peak width (∼14 nm). The sensing of trypsin is realized via the cleavage of peptide CF6 (Cys–Pro–Arg–Gly–R6G) and an extremely low detection limit of 0.1 μg mL−1 has been reached. Besides, owing to the high efficiency FRET process between the CPBQD/PMMA FM and cyclam–Cu2+, an unprecedented detection limit of Cu2+ has been pushed to 10−15 M. Furthermore, the pH value can be confirmed by the membrane in 10 ppb hydrazide R6G ethanol solution. The excellent optical characteristics of CPBQDs, high CPBQD subsurface concentration of the CPBQD/PMMA FM and robust durability of the PMMA coating all contribute to the outstanding sensitivity and stable detection performance of the CPBQD/PMMA FM.
Co-reporter:Xue Liu, Yanjie Hu, Guiqi Jia, Haoxuan Zhang, Hao Jiang and Chunzhong Li
Journal of Materials Chemistry A 2016 vol. 4(Issue 31) pp:12030-12035
Publication Date(Web):07 Jul 2016
DOI:10.1039/C6TA03335K
Rational construction of metal oxides-based electrode materials for Li-ion batteries (LIBs) is essential to simultaneously overcome their low conductivity and vulnerable nanostructure. Here, we demonstrate the design and synthesis of homologous V2O3/C box-in-box and V2O5 boxes as anodes and cathodes for all-nanobox based LIB full cells, which are subsequently obtained by thermal treatment in different atmospheres. While the V2O5 box cathodes can provide abundant active sites, short ionic diffusion distances and partial volume flexibility, the key design concept of the V2O3/C box-in-box is the carbon box-in-box, which further enhances the structural durability during lithiation/delithiation, hence giving rise to an extended lifespan. As proof-of-concept, the V2O3/C box-in-box anodes deliver a high reversible capacity of 641 mA h g−1 even after 1200 cycles at 1000 mA g−1, while the V2O5 box cathodes possess a specific capacity of 119 mA h g−1 at 10C with superior cycling stability. Importantly, a V2O3/C//V2O5 LIB full cell is assembled, which shows an impressive specific capacity of 97 mA h g−1 at 500 mA g−1 with a capacity retention of 81 mA h g−1 even after 100 cycles based on the cathode material weight.
Co-reporter:Yanyan Liu, Hongliang Jiang, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Journal of Materials Chemistry A 2016 vol. 4(Issue 5) pp:1694-1701
Publication Date(Web):06 Jan 2016
DOI:10.1039/C5TA10551J
The development of efficient and cheap bifunctional oxygen electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) to be applied in rechargeable metal–air batteries and unitized generative fuel cells (URFCs) operated with alkaline electrolytes is highly crucial and challenging. Here we report high-performance bifunctional electrocatalysts of transition metal nanoparticles encapsulated in nitrogen-doped carbon nanotubes (M/N-CNTs, M = Fe, Co, and Ni). The optimized Co/N-CNT hybrid shows the highest efficient bifunctional catalytic activity and excellent stability towards both the ORR and OER. The oxygen electrode activity parameter ΔE (the criteria for judging the overall catalytic activity of bifunctional electrocatalysts) value for Co/N-CNTs is 0.78 V, which surpasses those of Pt/C and RuO2 catalysts and most of the non-precious metal based bifunctional electrocatalysts reported in the previous literature studies. Furthermore, excellent long-term catalytic durability holds great promise in fields of renewable energy applications.
Co-reporter:Jianfei Huang, Shunan Zhao, Wei Chen, Ying Zhou, Xiaoling Yang, Yihua Zhu and Chunzhong Li
Nanoscale 2016 vol. 8(Issue 11) pp:5810-5814
Publication Date(Web):06 Nov 2015
DOI:10.1039/C5NR06512G
This communication reports fully electrochemical nanoengineering toward three-dimensionally grown thorn-like Cu nanowire arrays (CNWAs) as a highly efficient and durable electrocatalyst for hydrazine oxidation. Characterized by substantial negative shifting of the onset potential and an enlarged catalytic current density, the CNWAs afforded greatly enhanced hydrazine oxidation activity, even transcending that of the Pt/C catalyst at a higher reaction rate. The parameters of the electrochemical engineering and metallization methods were found to be essentially influential on the microstructure, and thus the electrocatalytic activity of the CNWAs. The present work typifies a flexible and expandible route toward integrated electrodes of metallic 1D nanostructures which are of interest in advancing the performance of cutting-edge electrochemical applications.
Co-reporter:Shasha Duan, Ke Yang, Zhihui Wang, Mengting Chen, Ling Zhang, Hongbo Zhang, and Chunzhong Li
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 3) pp:2187
Publication Date(Web):December 29, 2015
DOI:10.1021/acsami.5b10791
The combination of carbon nanomaterial with three-dimensional (3D) porous polymer substrates has been demonstrated to be an effective approach to manufacture high-performance stretchable conductive materials (SCMs). However, it remains a challenge to fabricate 3D-structured SCMs with outstanding electrical conductivity capability under large strain in a facile way. In this work, the 3D printing technique was employed to prepare 3D porous poly(dimethylsiloxane) (O-PDMS) which was then integrated with carbon nanotubes and graphene conductive network and resulted in highly stretchable conductors (OPCG). Two types of OPCG were prepared, and it has been demonstrated that the OPCG with split-level structure exhibited both higher electrical conductivity and superior retention capability under deformations, which was illustrated by using a finite element method. The specially designed split-level OPCG is capable of sustaining both large strain and repeated deformations showing huge potential in the application of next-generation stretchable electronics.Keywords: carbon nanotubes; conductive; graphene; porous PDMS; stretchable; three-dimensional printing
Co-reporter:Haoxuan Zhang, Shilong Jing, Yanjie Hu, Hao Jiang, Chunzhong Li
Journal of Power Sources 2016 Volume 307() pp:214-219
Publication Date(Web):1 March 2016
DOI:10.1016/j.jpowsour.2015.12.107
•Silicon hollow nanosheets are synthesized by a magnesiothermic reduction strategy.•A flexible freestanding Si/rGO film has been realized by layer-by-layer assembly.•The durable Si/rGO film anode shows intriguing performances in a flexible full LIB.The fabrication of flexible freestanding electrodes with superior electrochemical performance is challenging now in consumer electronics miniaturization. Herein, we demonstrate a simple and scalable synthesis of hollow silicon nanosheets, which then hybridizes with rGO into flexible films by layer-by-layer assembly process. The resulting Si/rGO films, when applied as a free-standing LIBs anode, exhibit a high reversible specific capacity of 904 mAh g−1 at 200 mA g−1 (about 2 times higher than theoretical value of graphite anode), and meanwhile maintain a long cycle life (650 mAh g−1 after 150 cycles). In addition, a flexible full battery has also been assembled based on the flexible film as an anode and the commercial LiCoO2 as a cathode, which impressively delivers a high specific capacity of 700 and 613 mAh g−1 at 50 mA g−1 after 15 cycles in flat and bent state, respectively. Such intriguing electrochemical performances can be mainly attributed to the two-dimensional hollow nanostructure of silicon and their strong synergistic effect with rGO. It is reckoned that our Si/rGO films are a promising anode for advanced flexible LIBs.
Co-reporter:Lei Xu, Yanjie Hu, Haoxuan Zhang, Hao Jiang, and Chunzhong Li
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 8) pp:4251
Publication Date(Web):July 11, 2016
DOI:10.1021/acssuschemeng.6b00741
To address the large volume change and polysulfide dissolution of FeS2-based materials for lithium-ion batteries (LIBs), we demonstrate the synthesis of FeS2 nanoparticles encapsulated in carbon nanotubes (CNTs) by a confined reaction. There is sufficient void space between adjacent FeS2 nanoparticles for guaranteeing the highly structural integrity. The resultant FeS2/CNT hybrids, when served as anode materials for LIBs, predictably exhibit a very stable capacity retention of 800 mAh g–1 over 200 cycles at 200 mA g–1. Even at 2000 mA g–1, they still deliver high-rate and long-life performance with a high specific capacity of 525 mAh g–1 after 1000 cycles. Such a kind of encapsulated structure is helpful for enhancing rate capability and cycling stability in LIBs applications. Importantly, the present confined reaction strategy can be extensively applied to synthesize other analogous hybrids for energy storage and conversion.Keywords: Confined synthesis; Encapsulated structure; FeS2; Lithium-ion batteries
Co-reporter:Dayong Ren, Yanjie Hu, Haibo Jiang, Zongnan Deng, Saha Petr, Hao Jiang, and Chunzhong Li
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 3) pp:1148
Publication Date(Web):January 7, 2016
DOI:10.1021/acssuschemeng.5b01218
The preparation of few-layered ultrasmall MoS2 nanosheets inlayed into carbon frameworks is challenging to date. Herein, we realize the synthesis of such meaningful nanohybrids (labeled as MoS2/CFs hybrids) by a simple salt-templating protocol, where NaCl particles are chosen as a sacrificial template to grow MoS2 crystals on the surface during the glucose carbonization, which meanwhile effectively inhibits their growth and stacking. In regard to electrochemical energy storage and conversion, the resulting MoS2/CFs hybrids are beneficial for providing substantial and accessible electroactive sites as well as rapid electrons/ions transfer. The present hybrids, when applied as lithium-ion batteries anode materials, exhibit a remarkably enhanced reversible specific capacity as high as 1083.5 mAh g–1 at 200 mA g–1 with fast charge/discharge capability (465.4 mAh g–1 at 6400 mA g–1), which is much higher than the exfoliated MoS2 nanosheets (only 97.6 mAh g–1 at 6400 mA g–1) and the commercial graphite. More impressively, our MoS2/CFs hybrids simultaneously possess a superior cycle life with negligible capacity loss after 400 cycles at 1600 mA g–1. In addition to the excellent lithium ion storage, our MoS2/CFs hybrids may concurrently exhibit some intriguing properties for applications in other energy-related fields.Keywords: Carbon frameworks; Few-layered MoS2; Lithium-ion battery; Nanohybrids; Salt-templating
Co-reporter:Yuanwei Wang, Yihua Zhu, Xiaoling Yang, Jianhua Shen, Xueqin Li, Shaohong Qian, Chunzhong Li
Electrochimica Acta 2016 Volume 211() pp:92-100
Publication Date(Web):1 September 2016
DOI:10.1016/j.electacta.2016.05.216
•NaYF4@SiO2crystalsareembeddedintoTiO2mesoporousmicrospheressimplily. (*).•Single-crystal-likeTiO2 mesochannels can increase conductivity and dye adsorption.•NaYF4@SiO2 crystals can increase NIR light upconversion harvest.•N@S@T microspheres can increase light scattering.•The η of the DSSCs with N@S@T-150 is 9.10%, increased by 26.39%.The β-NaYF4:Yb3+,Er3+@SiO2@TiO2 (N@S@T) mesoporous microspheres have been successfully synthesized via a simple evaporation-driven oriented assembly method (EDOA) and applied as multifunctional photoanode films on top of commercial P25 layers in dye-sensitized solar cells (DSSCs). Structural characterizations indicated that N@S@T mesoporous microspheres consisted of uniform β-NaYF4:Yb3+,Er3+ nanocrystals, SiO2 insulating middle shell and single-crystal-like anatase TiO2 shell exposed with (101) facets. Studies revealed that introducing β-NaYF4:Yb3+,Er3+@SiO2 into TiO2 mesoporous microspheres would remarkably enhance the short-circuit current density (Jsc). The SiO2 insulating middle shell played an role in packaging upconvertion nanoparticles (UCNPs) into TiO2 mesoporous microspheres, which were constructed to effectively transfer photoinduced electrons and adsorb more dye molecules, benefitting from their high specific surface areas. DSSCs with the optimal doping amount of UCNPs exhibited the Jsc value of 14.95 mA cm−2 and conversion efficiency of 9.10%, which was a notable enhancement of 26.39% in efficiency compared with commercial P25 based DSSCs. Our work demonstrated that introducing N@S@T into photoanodes was an effective method of improving the overall performance of DSSCs.
Co-reporter:Yun Wang, Ling Zhang, Yanjie Hu, Chunzhong Li
Journal of Materials Science & Technology 2016 Volume 32(Issue 3) pp:251-258
Publication Date(Web):March 2016
DOI:10.1016/j.jmst.2015.11.008
A new type of transparent scratch resistant coatings including in-situ modified SiO2 (g-SiO2) in flame spray pyrolysis (FSP) process was prepared. The maximum content of g-SiO2 in the coating was 15 wt%, which is higher than that of SiO2 modified by traditional wet chemical route (l-SiO2, only 10 wt%). The results of transmission electron microscopy have demonstrated that in-situ surface modified g-SiO2 particles dispersed well with smaller agglomerates in the final coating, which was much better than the particles modified via wet chemical route. Visible light transmittance and haze tests were introduced to characterize the optical quality of the films. All coatings were highly transparent with the visible light transmittance of above 80%, especially for coatings containing g-SiO2, which exhibited slightly higher visible light transmittance than l-SiO2 embedded one. The haze value of coatings incorporated with 15 wt% g-SiO2 was 1.85%, even lower than the coating with 5 wt% l-SiO2 (haze value of 2.09%), indicating much better clarity of g-SiO2. The excellent optical property of g-SiO2 filled coatings was attributed to the good dispersion and distribution of particles. Nano-indention and nano-scratch tests were conducted to investigate the scratch resistance of coatings on nano-scale. The surface hardness of the coatings rose by 18% and 14%, and the average friction coefficient decreased by 15% and 11%, respectively, compared to the neat coat due to the addition of 10 wt% g-SiO2 and l-SiO2. The pencil hardness of the coating with 15 wt% g-SiO2 increased from 2B for the neat coating to 2H. However, the pencil hardness of coating with 10 wt% l-SiO2 was only H. The results showed that the g-SiO2 embedded coatings exhibited higher scratch resistance and better optical properties.
Co-reporter:Hao Jiang, Haoxuan Zhang, Yao Fu, Shaojun Guo, Yanjie Hu, Ling Zhang, Yu Liu, Honglai Liu, and Chunzhong Li
ACS Nano 2016 Volume 10(Issue 1) pp:1648
Publication Date(Web):December 21, 2015
DOI:10.1021/acsnano.5b07367
One of the biggest challenging issues of carbon nanomaterials for Li ion batteries (LIBs) is that they show low initial Coulombic efficiency (CE), leading to a limited specific capacity. Herein, we demonstrate a simple template self-volatilization strategy for in situ synthesis of mesoporous carbon nanotube/Ag nanoparticle (NP) hybrids (Ag-MCNTs) to boost the LIBs’ performance. The key concept of Ag-MCNTs for enhancing LIBs is that a small trace of Ag NPs on MCNTS can greatly restrict the formation of a thicker solid electrolyte interphase film, which has been well verified by both transmission electron microscopy results and quantum density functional theory calculations, leading to the highest initial CE in all the reported carbon nanomaterials. This uncovered property of Ag NPs from Ag-MCNTs makes them exhibit a very high reversible capacity of 1637 mAh g–1 after 400 discharge/charge cycles at 100 mA g–1, approximately 5 times higher than the theoretical value of a graphite anode (372 mAh g–1), excellent rate capability, and long cycle life.Keywords: Ag nanoparticle; carbon nanotube; Coulombic efficiency; lithium ion battery; solid electrolyte interphase;
Co-reporter:Jianhua Shen, Yihua Zhu, Hao Jiang, Chunzhong Li
Nano Today 2016 Volume 11(Issue 4) pp:483-520
Publication Date(Web):August 2016
DOI:10.1016/j.nantod.2016.07.005
•The recent developments of the synthesis 3D architectures methods from each classical 2D nanosheets were highlighted.•The different fields of application were provided a significant enhancement in the efficacy as compared to 2D analogues.•3D porous structure possess the high electrochemical stability and the promise of high elasticity and mechanical stability.•3D architectures materials will exhibit their unique excellent performances in the industrial production in the future.The discovery of graphene attracted great interest because of the potential prospects of which in both basic and applied research. And other kinds of 2D graphene analogues, including hexagonal BN, carbon nitride, transition metal dichalcogenides, etc. derived from their layered bulk crystals, have also been extensively investigated because of their promising characters and potential applications. It is expected that these 2D nanosheets, in bulk or in composite materials, could maintain their extraordinary properties. However, the irreversible aggregation or accumulating of 2D nanosheets due to the strong van der Waals interactions, extremely decrease their accessible surface area. More recently, with the recognization of the tremendous interest of these 2D structures, scientists noticed that the performance of certain devices could be significantly improved by utilizing 3D architectures and/or aerogels due to the increase of unit activity of the materials. This review summarizes different synthetic process (such as assembly, chemical vapor deposition direct synthesis, in-situ confinement growth and so on) used for preparation of 2D graphene analogues based 3D architectures and/or aerogels containing either any or their composites. And the different fields of application for energy storage (including both supercapacitor and lithium ion battery applications), electrocatalysis, sensing and others are provided a significant enhancement in the efficacy as compared to their 2D analogues or even opened the path to novel application. In addition, some perspectives on the challenges and opportunities in this promising research area are also discussed.
Co-reporter:Hao Jiang;Dayong Ren;Haifeng Wang;Yanjie Hu;Shaojun Guo;Haiyang Yuan;Peijun Hu;Ling Zhang;Chunzhong Li
Advanced Materials 2015 Volume 27( Issue 24) pp:3687-3695
Publication Date(Web):
DOI:10.1002/adma.201501059
Co-reporter:Shilong Jing;Hao Jiang;Yanjie Hu;Jianhua Shen ;Chunzhong Li
Advanced Functional Materials 2015 Volume 25( Issue 33) pp:5395-5401
Publication Date(Web):
DOI:10.1002/adfm.201502330
To develop high-performance anode materials of lithium-ion batteries (LIBs) instead of commercial graphite for practical applications, herein, a layer of silicon has been well-anchored onto a 3D graphene/carbon nanotube (CNT) aerogels (CAs) framework with face-to-face contact and balanced open void by a simple chemical vapor deposition strategy. The engineered contact interface between CAs and Si creates high-efficiency channels for the rapid electrons and lithium ions transport, and meanwhile, the balanced open-void allows the free expansion of Si during cycling while maintaining high structural integrity due to the robust mechanical strength of 3D CAs framework. As a consequence, the as-synthesized Si/CAs nanohybrids are highly stable anode materials for LIBs with a high reversible discharge capacity (1498 mAh g−1 at 200 mA g−1) and excellent rate capability (462 mAh g−1 at 10 000 mA g−1), which is much better than Si/graphene-CNTs-mixture (51 mAh g−1 at 10 000 mA g−1). More significantly, it is found that the Si/CAs nanohybrids display no obvious capacity decline even after 2000 cycles at a high current density of 10 000 mA g−1. The present Si/CAs nanohybrids are one of the most stable Si-based anode materials ever reported for LIBs to date.
Co-reporter:Yihui Dai, Ling Chen, Vladimir Babayan, Qilin Cheng, Petr Saha, Hao Jiang and Chunzhong Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 42) pp:21337-21342
Publication Date(Web):14 Sep 2015
DOI:10.1039/C5TA06958K
We demonstrate the synthesis of ultrathin MnO2 nanoflakes grown on N-doped carbon nanoboxes, forming an impressive hierarchical MnO2/C nanobox hybrid with an average size of 500 nm, which exhibits an excellent electrochemical performance due to the unique structure, N-doping and strong synergistic effects between them. In addition, we also assembled a green asymmetric supercapacitor (ASC) using the as-synthesized MnO2/C nanoboxes as a positive electrode and the corresponding N-doped carbon nanoboxes as a negative electrode in a neutral aqueous electrolyte, aiming to further enhance its energy density by extending the operating potential. More significantly, our ASC device is able to reversibly cycle within a wide operating voltage of 2.0 V and delivers a maximum energy density of 39.5 W h kg−1 with superior cycling stability (∼90.2% capacitance retention after 5000 cycles). These intriguing results show that hollow nanostructures will be promising electrode materials for advanced supercapacitors.
Co-reporter:Xiaoyu Hou, Yanjie Hu, Hao Jiang, Yunfeng Li, Wenge Li and Chunzhong Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 18) pp:9982-9988
Publication Date(Web):17 Mar 2015
DOI:10.1039/C5TA01106J
SnOx nanocrystalline aggregates (NAs) encapsulated by an amorphous TiO2 layer have been successfully designed by a one-step flame spray pyrolysis (FSP). The synthesized SnOx NAs@TiO2 with different degrees of aggregations were composed of SnOx nanocrystallites ranging from 5 nm to 10 nm and a TiO2 layer with a thickness of 1–5 nm. The encapsulated TiO2 layer was introduced in situ by incorporating TiCl4 into the downstream of an FSP reactor, where TiO2 nucleated and grew in the surface of the SnOx NAs. The hydrolysis temperature of TiCl4 in a flame was controlled to synthesize amorphous TiO2 with intrinsic electrochemical features. As an anode in LIBs (Li-ion batteries), the SnOx NAs@TiO2 electrode showed superior cycle life and rate performance (capacity of 350 mA h g−1 after 300 cycles and 332 mA h g−1 at 1 A g−1) compared to pure SnOx or TiO2 electrodes. The remarkably enhanced Li+ storage performance is mainly attributed to the nanoscale of nanocrystalline aggregates, the core–shell structure of SnOx@TiO2 and the amorphous state of TiO2.
Co-reporter:Jianfei Huang, Huailong Li, Yihua Zhu, Qilin Cheng, Xiaoling Yang and Chunzhong Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 16) pp:8734-8741
Publication Date(Web):16 Mar 2015
DOI:10.1039/C5TA00847F
Commercial copper foams have been tailored by a highly scalable method combining room-temperature wet-chemical etching and hydroxide thermolysis into a three-dimensional copper oxide nanowire array–copper (3D-CuONA–Cu) composite with macroporous voids and large-area fur-like nanowire array structures, whose structures and compositions were studied employing electron microscopy, X-ray diffraction (XRD) and Raman spectroscopy. The 3D-CuONA–Cu composite monolith was used as a free-standing electrode for pseudo-capacitive energy storage and enzyme-free H2O2 detection. Thanks to the 3D electrode architecture and the high-density in situ formed electroactive nanoarrays, an enhanced capacitance of 608 mF cm−2 at 2 mV s−1 was achieved, with an 88.6% capacity retention after 4000 cycles observed at the high current density of 30 mA cm−2. For enzyme-free H2O2 sensing, an extraordinary sensitivity of 5.75 mA mM−1 cm−2 and a low detection limit of 0.56 μM were achieved. This prototype sensor also exhibited eligible selectivity and feasibility for real sample analysis.
Co-reporter:Yunfeng Li, Yanjie Hu, Jianhua Shen, Haibo Jiang, Guoquan Min, Shengjie Qiu, Zhitang Song, Zhuo Sun and Chunzhong Li
Nanoscale 2015 vol. 7(Issue 44) pp:18603-18611
Publication Date(Web):08 Oct 2015
DOI:10.1039/C5NR05586E
The rational design of nanoheterostructured materials has attracted much attention because of its importance for developing highly efficient LIBs. Herein, we have demonstrated that internal Mo6+ doped TiO2 nanocrystals in situ decorated with highly dispersed MoO3 clusters have been realized by a facile and rapid flame spray pyrolysis route for electrochemical energy storage. In such intriguing nanostructures, internal Mo6+ doping can improve the conductivity of electrode materials and facilitate rapid Li+ intercalation and ion transport and the heteroassembly of highly dispersed ultrafine MoO3 clusters with excellent electrochemical activity endows the TiO2 with extra Li+ ion storage ability as well as incorporates Mo6+. Thus, the as-prepared nanohybrid electrodes exhibit a high specific capacity and superior rate capability due to the maximum synergetic effect of TiO2, Mo6+ and ultrafine MoO3 clusters. Moreover, the aerosol flame process with a unique temperature gradient opens a new strategy to design novel hybrid materials by the simultaneous doping and heteroassembly engineering for next-generation LIBs.
Co-reporter:Jianfei Huang, Yihua Zhu, Xiaoling Yang, Wei Chen, Ying Zhou and Chunzhong Li
Nanoscale 2015 vol. 7(Issue 2) pp:559-569
Publication Date(Web):10 Nov 2014
DOI:10.1039/C4NR05620E
Convenient determination of glucose in a sensitive, reliable and cost-effective way has aroused sustained research passion, bringing along assiduous investigation of high-performance electroactive nanomaterials to build enzymeless sensors. In addition to the intrinsic electrocatalytic capability of the sensing materials, electrode architecture at the microscale is also crucial for fully enhancing the performance. In this work, free-standing porous CuO nanowire (NW) was taken as a model sensing material to illustrate this point, where an in situ formed 3D CuO nanowire array (NWA) and CuO nanowires pile (NWP) immobilized with polymer binder by conventional drop-casting technique were both studied for enzymeless glucose sensing. The NWA electrode exhibited greatly promoted electrochemistry characterized by decreased overpotential for electro-oxidation of glucose and over 5-fold higher sensitivity compared to the NWP counterpart, benefiting from the binder-free nanoarray structure. Besides, its sensing performance was also satisfying in terms of rapidness, selectivity and durability. Further, the CuO NWA was utilized to fabricate a flexible sensor which showed excellent performance stability against mechanical bending. Thanks to its favorable electrode architecture, the CuO NWA is believed to offer opportunities for building high-efficiency flexible electrochemical devices.
Co-reporter:Jianhua Shen, Yunfeng Li, Yunhe Su, Yihua Zhu, Hongliang Jiang, Xiaoling Yang and Chunzhong Li
Nanoscale 2015 vol. 7(Issue 5) pp:2003-2008
Publication Date(Web):16 Dec 2014
DOI:10.1039/C4NR06484D
Here, we demonstrate novel carbon–nitrogen quantum dots (CNQDs) by the hydrothermal method using melamine and glutaraldehyde. CNQDs are uniformly dispersed with particle diameters of 3–8 nm. These prepared CNQDs show excellent luminescence properties and the photoluminescent quantum yields of CNQDs with 365 nm emission are up to 31%. Interestingly, CNQDs possess the co-existence of both p- and n-type conductivities from the Mott–Schottky relationship. Furthermore, the electrochemical measurements reveal that CNQDs exhibit catalytic activity for the oxygen reduction reaction (ORR). However, the low electrical conductivity affects the ORR electrocatalytic activity. So the catalysis is conducted by chemical coupling of CNQDs on Ag nanoparticles (NPs), the resulting CNQD/Ag NP catalyst is demonstrated to possess superior electrocatalytic ability for the ORR in an alkaline medium.
Co-reporter:Xin Jiang, Xiaoling Yang, Yihua Zhu, Yifan Yao, Peng Zhao and Chunzhong Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 5) pp:2361-2369
Publication Date(Web):05 Dec 2014
DOI:10.1039/C4TA05913A
A novel hierarchical nanostructure composed of carbon coated Fe3O4 nanoparticles with seed-like morphology distributed on graphene (denoted as G/Fe3O4@C) is prepared as a high-capacity anode electrode for LIBs. β-FeOOH nanoseeds were first assembled on graphene by solvothermal treatment, followed by coating β-FeOOH nanoseeds with polydopamine via immersion in dopamine aqueous solution. Finally, G/Fe3O4@C is obtained after in situ phase transformation of β-FeOOH into Fe3O4 and simultaneous carbonization of the polydopamine nanocoating through thermal annealing at 500 °C. The thickness of the uniform and continuous carbon layer can be easily tailored by varying the polymerization time and the concentration of dopamine to balance the concurrent needs for high active material content and structural stability. The carbon layer can effectively prevent the agglomeration of Fe3O4 nanoparticles, which enables the reversible conversion reaction between Fe3O4 and lithium, and significantly improves the mechanical stability of electrodes by accommodating volume expansion of Fe3O4 nanoparticles during the electrochemical cycling. Meanwhile, the combination of graphene and the carbon shell improves the electrochemical reaction kinetics of the electrode. As a result, the obtained G/Fe3O4@C nanocomposites with the optimal carbon shell thickness of about 1.2 nm exhibit high reversible capacities with remarkable cyclic retention at different current rates (1344 mA h g−1 after cycling at 0.5 C for 200 cycles, 743 mA h g−1 after further cycling at 2 C for another 200 cycles) and excellent rate performance (150 mA h g−1 at 20 C) as anodes in lithium ion batteries.
Co-reporter:Jianhua Shen, Yunfeng Li, Yihua Zhu, Xiaoling Yang, Xiuzhong Yao, Jun Li, Guangjian Huang and Chunzhong Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 14) pp:2873-2882
Publication Date(Web):18 Feb 2015
DOI:10.1039/C5TB00041F
The facile fabrication of Gd-labeled superparamagnetic Fe3O4 nanoparticles (NPs) and fluorescent CuInS2 (CIS) quantum dots conjugated with arginine-glycine-aspartic acid (RGD) peptides has been demonstrated, for tri-mode targeted T1-, T2-weighted magnetic resonance (MR) and fluorescence imaging of pancreatic cancer. The core–shell nanocomposites formed are water-dispersible, stable and biocompatible, as confirmed by MTT assay on BXPC-3 cells. Relaxivity measurements show a T1 relaxivity (r1) of 1.56 mM−1 s−1 and a T2 relaxivity (r2) of 23.22 mM−1 s−1, which enable T1- and T2-weighted MR imaging of cancer cells in vitro and in vivo. The MR imaging data clearly indicate that the multifunctional NPs can specifically target cancer cells with αvβ3 integrin over-expression on the cell surface, through a receptor-mediated delivery pathway. The T1-weighted positive and T2-weighted negative enhancement in the MR imaging significantly improves the diagnosis accuracy, and fluorescence imaging of tumor tissue can assist in clinical surgery. These findings suggest that these multifunctional NPs could be used as a platform for bimodal imaging (both MR and fluorescence) in various biological systems.
Co-reporter:Mengting Chen, Shasha Duan, Ling Zhang, Zhihui Wang and Chunzhong Li
Chemical Communications 2015 vol. 51(Issue 15) pp:3169-3172
Publication Date(Web):15 Dec 2014
DOI:10.1039/C4CC09367D
We have manufactured a highly conductive and stretchable composite by backfilling the 3D graphene–PEDOT:PSS skeleton with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 24 S cm−1 with only 1.5 wt% graphene and 1.5 wt% PEDOT:PSS loading, and its resistance increased only 35% when stretched to 80% strain.
Co-reporter:Xiaoyu Hou, Yanjie Hu, Hao Jiang, Yunfeng Li, Xiaofeng Niu and Chunzhong Li
Chemical Communications 2015 vol. 51(Issue 91) pp:16373-16376
Publication Date(Web):10 Sep 2015
DOI:10.1039/C5CC06123G
Sn@Ni3Sn4 embedded nanocable-like carbon hybrids have been successfully prepared through a novel gas-phase route. The introduced Ni3Sn4 layer not only suppresses the tin-induced volume expansion, but also provides more voids and vacancies in the interior of the nanocables. When used as the anode in LIBs, the Sn@Ni3Sn4/C hybrids exhibit a long cycle life (360 mA h g−1 at 1 A g−1 after 1500 cycles).
Co-reporter:Hongliang Jiang, Yifan Yao, Yihua Zhu, Yanyan Liu, Yunhe Su, Xiaoling Yang, and Chunzhong Li
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 38) pp:21511
Publication Date(Web):September 15, 2015
DOI:10.1021/acsami.5b06708
It is highly crucial and challenging to develop bifunctional oxygen electrocatalysts for oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) in rechargeable metal-air batteries and unitized regenerative fuel cells (URFCs). Herein, a facile and cost-effective strategy is developed to prepare mesoporous Fe–N-doped graphene-like carbon architectures with uniform Fe3C nanoparticles encapsulated in graphitic layers (Fe3C@NG) via a one-step solid-state thermal reaction. The optimized Fe3C@NG800-0.2 catalyst shows comparable ORR activity with the state-of-the-art Pt/C catalyst and OER activity with the benchmarking RuO2 catalyst. The oxygen electrode activity parameter ΔE (the criteria for judging the overall catalytic activity of bifunctional electrocatalysts) value for Fe3C@NG800-0.2 is 0.780 V, which surpasses those of Pt/C and RuO2 catalysts as well as those of most nonprecious metal catalysts. Significantly, excellent long-term catalytic durability holds great promise in fields of rechargeable metal-air batteries and URFCs.Keywords: graphitic layers; iron carbide; oxygen electrocatalysts; oxygen evolution reaction; oxygen reduction reaction
Co-reporter:Zongnan Deng, Yanjie Hu, Dayong Ren, Shaoliang Lin, Hao Jiang and Chunzhong Li
Chemical Communications 2015 vol. 51(Issue 72) pp:13838-13841
Publication Date(Web):21 Jul 2015
DOI:10.1039/C5CC05069C
The reciprocal hybridization of MoO2 nanoparticles and few-layer MoS2 has been realized via a facile hydrothermal reaction. The resulting MoO2/MoS2 hybrids exhibit a high reversible specific capacity of 1103 mA h g−1 at 0.2 A g−1 with a high rate performance (273 mA h g−1 at 6.4 A g−1) and an excellent cycling stability (∼92% capacity retention after 800 cycles) mainly due to the strong synergistic effect between them.
Co-reporter:Huailong Li, Lixue Jiang, Qilin Cheng, Ying He, Vladimir Pavlinek, Petr Saha, Chunzhong Li
Electrochimica Acta 2015 Volume 164() pp:252-259
Publication Date(Web):10 May 2015
DOI:10.1016/j.electacta.2015.02.218
•A two-step redox approach is developed to the synthesis of MnO2 nanoflakes/hierarchical porous carbon nanocomposite.•The MnO2 nanoflakes/HPCs composite with 75 wt% MnO2 exhibits well defined hierarchical structure with relatively high specific surface area.•The MnO2 nanoflakes/HPCs-75 composite possesses the highest specific capacitance of 417.2 F g−1 at a scan rate of 20 mV s−1 and extraordinary cycling stability.A facile strategy is developed for the synthesis of MnO2 nanoflakes/hierarchical porous carbon spheres (HPCs) nanocomposites via a two-step redox process. The external MnO2 nanoflakes with thickness of ∼10 nm deposited on the surface of the HPCs result in the formation of hierarchical architecture of the composites, while the internal MnO2 layer stabilizes the interaction between MnO2 nanoflakes and HPCs. The resultant composites still retain porous structure after removal of mesoporous SiO2 template and exhibit relatively high specific surface area. The morphology control of the composites can be easily achieved by varying the initial content of Mn(NO3)2 and KMnO4. Electrochemical performance of the composites as supercapacitor electrode materials was evaluated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy techniques. The MnO2 nanoflakes/HPCs composite with 75 wt% MnO2 possesses the highest specific capacitance at a high scan rate or current density (417.2 F g−1 at 20 mV s−1 and 326.9 F g−1 at 1 A g−1, respectively) and extraordinary cycling stability (slightly over 100% capacitance retention after 10000 cycles at a scan rate of 100 mV s−1), which are superior to other reported MnO2/carbon composites. The results suggest that rational design and synthesis of MnO2/porous carbon composite electrode materials with maximum electrochemical active sites is important to further improve their electrochemical performance.
Co-reporter:Hongmei Ding, Hao Jiang, Zhengju Zhu, Yanjie Hu, Feng Gu, Chunzhong Li
Electrochimica Acta 2015 Volume 157() pp:205-210
Publication Date(Web):1 March 2015
DOI:10.1016/j.electacta.2015.01.007
•A three-dimensional ternary SnO2@PANI/rGO nanohybrids has been synthesized via dip-coating method.•PANI acts as the conductive matrix as well as a good binding agent of SnO2 nanoparticles and graphene sheets, greatly improving the electrochemical performance.•The nanohybtrids, when applied as LIBs,exhibit a high reversible specific capacity of 772 mA h g−1 at 100 mA g−1 with excellent rate capability and high cycling stability.A three-dimensional (3D) nanostructure composed of ternary polyaniline/SnO2/graphene (SnO2@PANI/rGO) nanohybrids were successfully developed and prepared as anode materials for lithium ion batteries (LIBs) by a simple dip-coating of SnO2@polyaniline (SnO2@PANI) and graphene dispersion on Cu foam. In such smart nanostructures, polyaniline (PANI) acts as the conductive matrix as well as a good binding agent of SnO2 nanoparticles and graphene sheets, greatly improving the rate performance to a great extent. The as-prepared ternary nanohybrids exhibit a high reversible specific capacity of 772 mA h g−1 at 100 mA g−1 with excellent rate capability (268 mA h g−1 at 1000 mA g−1), more significantly, after 100 cycles at 100 mA g−1, our ternary nanohybrids still maintain a high specific capacity of 749 mA h g−1, which is much better than SnO2/rGO(458 mA h g−1 at 100 mA g−1), SnO2@PANI (480 mA h g−1 at 100 mA g−1) and pure SnO2 nanoparticles (300 mA h g−1 at 100 mA g−1). Such intriguing electrochemical performance is mainly attributed to the strong synergistic effects among SnO2, polyaniline and graphene. It is reckoned that the present 3D SnO2@PANI/rGO nanohybrids can serve as a promising anode material for LIBs.
Co-reporter:Shasha Duan, Ling Zhang, Zhihui Wang and Chunzhong Li
RSC Advances 2015 vol. 5(Issue 115) pp:95280-95286
Publication Date(Web):05 Nov 2015
DOI:10.1039/C5RA19148C
Excellent optoelectric and adhesive properties are two crucial parts for the application of transparent conductive electrodes (TCEs). In this work, AgNWs are composited with PEDOT:PSS to prepare high-performance TCEs using a one-step rod-coating approach, where AgNWs are buried in PEDOT:PSS resulting in largely weakened roughness and lowered sheet resistance from 164 Ω sq−1 to 16 Ω sq−1 at 90.4% optical transmittance. Besides, the addition of Zonyl improved the wettability of hydrophilic PEDOT:PSS on hydrophobic substrates, which enhanced the adhesion of the AgNWs–PEDOT:PSS film. A sulfuric acid post-process further strengthened the interaction between PEDOT:PSS and the organic substrate contributing improved adhesion of the AgNWs–PEDOT:PSS composite film. The as-prepared film exhibits favorable stability in both cyclic deformations and solvent environments. The solution-processed fabrication, outstanding photoelectric performance and strong adhesion imparts the AgNWs–PEDOT:PSS with tremendous potential in the application of flexible electronics.
Co-reporter:Yao Fu, Hao Jiang, Yanjie Hu, Yihui Dai, Ling Zhang, and Chunzhong Li
Industrial & Engineering Chemistry Research 2015 Volume 54(Issue 15) pp:3800-3805
Publication Date(Web):March 30, 2015
DOI:10.1021/ie504659h
To overcome the poor cycling stability of LiMn2O4 cathode materials without sacrificing the specific capacity, we demonstrate a new strategy for synergistically enhancing their electrochemical performance by combining the advantages of Al doping and the exposure of highly active facets. Specifically, Al doping can suppress Mn dissolution in the electrolyte, leading to an outstanding cycling stability. In addition, the exposure of highly active facets can greatly enhance the specific capacity and rate capability, while also compensating for the capacity loss caused by Al doping. As a consequence, the as-prepared Al-doped LiMn2O4 truncated octahedrons exhibit a far superior performance in both rate capacity and cycling stability than the pure LiMn2O4 octahedrons and the LiMn2O4 truncated octahedrons. Our work is meaningful not only for the synthesis of high-performance LiAl0.1Mn1.9O4 truncated octahedrons, but also for providing new insight into the development of high-performance LiMn2O4 cathode materials.
Co-reporter:Wenqiong Ye, Ling Zhang and Chunzhong Li
RSC Advances 2015 vol. 5(Issue 32) pp:25450-25456
Publication Date(Web):05 Mar 2015
DOI:10.1039/C5RA02126J
SiO2@poly(methyl methacrylate)–reduced graphene oxide (SiO2@PMMA–rGO) composites with outstanding thermal stability, robust mechanical performance and excellent conductivity have been prepared by dispersion polymerization and electrostatic assembly based colloidal blending. The simultaneous construction of well-segregated silica structures and interconnected graphene networks, not only efficiently avoids agglomeration of the incorporated nanofillers, but also ensures enhanced interfacial adhesion between the fillers and the PMMA matrix, endowing the resultant composite with high performance. Specifically, compared to the host polymer, the composite with collaborative structure exhibits high thermal stability, i.e. the decomposition temperature increases by 80 °C and shows robust mechanical properties with a 108% increase in modulus and a 125% improvement in hardness. Besides, an ultra-low percolation threshold of 0.23 vol% is also achieved and the electrical conductivity reached 15.1 S m−1 with only 2.7 vol% graphene loading, which is ∼8 orders of magnitude higher than that for SiO2–PMMA–rGO (where SiO2, PMMA and rGO were simply compounded without forming synergetic structures) with the same rGO loading. These results demonstrate that the SiO2@PMMA–rGO composite has great potential to be applied as mechanical, thermal, and electrical materials.
Co-reporter:Ying Zhou, Yihua Zhu, Xiaoling Yang, Jianfei Huang, Wei Chen, Xiaoming Lv, Cuiyan Li and Chunzhong Li
RSC Advances 2015 vol. 5(Issue 62) pp:50454-50461
Publication Date(Web):26 May 2015
DOI:10.1039/C5RA08243A
Heterostructured Au nanoparticle decorated Fe3O4@TiO2 composite magnetic microspheres (MSs) were synthesized by grafting Au nanoparticles onto 3-aminopropyltrimethoxysilane (APTMS) modified Fe3O4@TiO2 MSs. Significantly, by varying the reaction conditions, the as-synthesized Fe3O4@TiO2@Au MSs showed high performance in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4 under visible light. In addition, the as-prepared Fe3O4@TiO2@Au MSs can clean themselves by photocatalytic degradation of organic molecules, and can be reused for several cycles with convenient magnetic separability. This approach provided a platform based on the synergy of varying components under suitable conditions to optimize the catalytic ability.
Co-reporter:Wenqiong Ye, Ling Zhang, Guowei Feng, Jing Ye, and Chunzhong Li
Industrial & Engineering Chemistry Research 2015 Volume 54(Issue 30) pp:7459-7464
Publication Date(Web):July 8, 2015
DOI:10.1021/acs.iecr.5b01921
Calcium carbonate@methyl methacrylate-polyvinyl chloride (CaCO3@PMMA–PVC) nanocomposites with outstanding mechanical performance have been successfully prepared. Precise control over the CaCO3 surface modification via a green, facile, and reproducible seed dispersion polymerization, not only efficiently avoids agglomeration of the incorporated nanofillers, but also ensures enhanced interfacial adhesion between components, endowing the resultant composite with high performance. Specifically, the maximum tensile strength of PVC composites was achieved when the addition of CaCO3@PMMA NPs is 4 wt %, and the grafting content is 25%. Compared to pure PVC (P-PVC), the composite shows robust mechanical properties with a 116.7% increase in modulus and a 57.0% improvement in hardness.
Co-reporter:Mengting Chen;Ling Zhang;Shasha Duan;Shilong Jing;Hao Jiang ;Chunzhong Li
Advanced Functional Materials 2014 Volume 24( Issue 47) pp:7548-7556
Publication Date(Web):
DOI:10.1002/adfm.201401886
Here, a novel and facile method is reported for manufacturing a new stretchable conductive material that integrates a hybrid three dimensional (3D) carbon nanotube (CNT)/reduced graphene oxide (rGO) network with a porous poly(dimethylsiloxane) (p-PDMS) elastomer (pPCG). This reciprocal architecture not only alleviates the aggregation of carbon nanofillers but also significantly improves the conductivity of pPCG under large strains. Consequently, the pPCG exhibits high electrical conductivity with a low nanofiller loading (27 S m−1 with 2 wt% CNTs/graphene) and a notable retention capability after bending and stretching. The simulation of the mechanical properties of the p-PDMS model demonstrates that an extremely large applied strain (εappl) can be accommodated through local rotations and bending of cell walls. Thus, after a slight decrease, the conductivity of pPCG can continue to remain constant even as the strain increases to 50%. In general, this architecture of pPCG with a combination of a porous polymer substrate and 3D carbon nanofiller network possesses considerable potential for numerous applications in next-generation stretchable electronics.
Co-reporter:Xiaoqing Zhang, Yihua Zhu, Xiaoling Yang, Ying Zhou, Yifan Yao and Chunzhong Li
Nanoscale 2014 vol. 6(Issue 11) pp:5971-5979
Publication Date(Web):21 Mar 2014
DOI:10.1039/C4NR00975D
Herein, we demonstrate the design and fabrication of multifunctional triplex Fe3O4@TiO2@Au core–shell magnetic microspheres (MSs), which show excellent surface enhanced Raman scattering (SERS) activity with high reproducibility and stability. In addition, due to their excellent catalytic properties, the as-prepared Fe3O4@TiO2@Au magnetic MSs can clean themselves by photocatalytic degradation of target molecules adsorbed onto the substrate under irradiation with visible light, and can be re-used for several cycles with convenient magnetic separability. The influence of the size and distribution of Au nanoparticles (NPs) on the Fe3O4@TiO2 beads is investigated. The optimized samples employing Au NPs of 15 nm size and an areal density of about 2120 Au NPs on every MS show the best SERS activity and recyclable performance. The experimental results show that these magnetic MSs indicate a new route in eliminating the ‘single-use’ problem of traditional SERS substrates and exhibit their applicability as analytical tools for the detection of different molecular species.
Co-reporter:Mengting Chen, Ling Zhang, Shasha Duan, Shilong Jing, Hao Jiang, Meifang Luo and Chunzhong Li
Nanoscale 2014 vol. 6(Issue 7) pp:3796-3803
Publication Date(Web):17 Jan 2014
DOI:10.1039/C3NR06092F
New flexible and conductive materials (FCMs) comprising a quartz fiber cloth (QFC) reinforced multi-walled carbon nanotubes (MWCNTs)–carbon aerogel (QMCA) and poly(dimethylsiloxane) (PDMS) have been successfully prepared. The QMCA–PDMS composite with a very low loading of MWCNTs (∼1.6 wt%) demonstrates enhanced performance in tensile strength (129.6 MPa), modulus (3.41 GPa) and electromagnetic interference (EMI) shielding efficiency (SE) (∼16 dB in X-band (8.2–12.4 GHz) region). Compared to the QC (where MWCNTs were simply deposited on the QFCs without forming aerogel networks) based PDMS composite, a ∼120%, 330% and 178% increase of tensile strength, modulus, and EMI SE was obtained, respectively. Moreover, the EMI SE of the QMCA–PDMS composite can further reach 20 dB (a SE level needed for commercial applications) with only 2 wt% MWCNTs. Furthermore, the conductivity of the QMCA–PDMS laminate can reach 1.67 S cm−1 even with very low MWCNTs (1.6 wt%), which still remains constant even after 5000 times bending and exhibits an increase of ∼170% than that of MWCNT–carbon aerogel (MCA)–PDMS at 20% strain. Such intriguing performances are mainly attributed to their unique networks in QMCA–PDMS composites. In addition, these features can also protect electronics against harm from external forces and EMI, giving the brand-new FCMs huge potential in next-generation devices, like E-skin, robot joints and so on.
Co-reporter:Peng Zhao, Yuanyuan Wu, Yihua Zhu, Xiaoling Yang, Xin Jiang, Jingfan Xiao, Yuanxing Zhang and Chunzhong Li
Nanoscale 2014 vol. 6(Issue 7) pp:3804-3809
Publication Date(Web):27 Feb 2014
DOI:10.1039/C3NR06549A
Here, we report a simple and ultrasensitive upconversion fluorescent strip sensor based on NaYF4:Yb,Er nanoparticles (NPs) and the lateral flow immunochromatographic assay (LFIA). Carboxyl-modified β-NaYF4:Yb,Er NPs were successfully synthesized by a facile one-pot solvothermal approach, upon further coupling with monoclonal antibody, the resultant UCNPs-antibody conjugates probes were used in LFIA and served as signal vehicles for the fluorescent reporters. V. anguillarum was used as a model analyte to demonstrate the use of this strip sensor. The limit of the detection for the fluorescent strip was determined as 102 CFU mL−1, which is 100 times lower than those displayed by enzyme-linked immunosorbent assays, while the time needed for the detection was only 15 min. Furthermore, no cross-reaction with other eight pathogens was found, indicating the good specificity of the strip. This developed LFIA would offer the potential as a useful tool for the quantification of pathogens analysis in the future.
Co-reporter:Junchao Huo, Yanjie Hu, Hao Jiang, Wenjuan Huang and Chunzhong Li
Journal of Materials Chemistry A 2014 vol. 2(Issue 22) pp:8266-8272
Publication Date(Web):04 Mar 2014
DOI:10.1039/C4TA00083H
Novel SnO2 nanorod@TiO2 hybrid materials have been designed and synthesized by in situ coating a layer of TiO2 on the surface of the SnO2 nanorods using a modified flame spray pyrolysis (FSP) approach. The as-prepared SnO2 nanorod@TiO2 hybrid materials have a length of up to about 150 nm and a diameter of about 40 nm. TiO2 is uniformly coated on well-crystallized SnO2 nanorods with a thickness of about 10 nm. The dye-sensitized solar cell (DSC) properties of the SnO2 nanorod@TiO2 hybrid materials were investigated. Owing to the superior light scattering effect, advantages of suppression charge recombination, and increased dye loading, the power conversion efficiency (η) of the SnO2 nanorod@TiO2 hybrid material electrode is 6.98%, much higher than that of the SnO2 nanorods electrode (3.95%) and P25 electrode (5.27%).
Co-reporter:Xin Jiang, Xiaoling Yang, Yihua Zhu, Hongliang Jiang, Yifan Yao, Peng Zhao and Chunzhong Li
Journal of Materials Chemistry A 2014 vol. 2(Issue 29) pp:11124-11133
Publication Date(Web):08 May 2014
DOI:10.1039/C4TA01348D
A three-dimensional (3D) foam architecture of ultrafine TiO2 nanoparticles embedded in N-doped graphene networks (denoted as UTO/NGF) is prepared via a facile hydrothermal self-assembly and a subsequent freeze-drying scheme. The obtained UTO/NGF possesses a large surface area, macro/mesoporous structure, and high-level nitrogen content (7.34%). Such a unique hierarchical architecture provides multidimensional electronic network, enlarged contact area between electrolyte and electrode, and numerous open channels for the access of the electrolyte, thus favoring diffusion kinetics for both electrons and lithium ions. Meanwhile, nitrogen doping can further improve the electrical conductivity and electrochemical activity of the obtained composite during electrochemical processes. As a consequence, the UTO/NGF exhibits high reversible capacities with remarkable cyclic retention at different current rates (165 mA h g−1 after 200 cycles at 1 C rate, 143 mA h g−1 after 200 cycles at 5 C rate) and excellent rate performance (96 mA h g−1 at 20 C) as anodes in lithium ion batteries.
Co-reporter:Shilong Jing, Hao Jiang, Yanjie Hu and Chunzhong Li
Nanoscale 2014 vol. 6(Issue 23) pp:14441-14445
Publication Date(Web):13 Oct 2014
DOI:10.1039/C4NR05469E
In order to mitigate the drastic volumetric expansion (>300%) of silicon (Si) during the lithiation process, we demonstrate the synthesis of novel Si nanowire arrays (n-SNWAs) with a coral-like surface on Cu foam via a one-step CVD method, in which the Cu foam can simultaneously act as a catalyst and current collector. The unique coral-like surface endows n-SNWAs with a high structural integrity, which is beneficial for enhancing their electrochemical performance. In addition, the as-prepared n-SNWAs on Cu foam can be directly applied as the anode for lithium-ion batteries (LIBs), exhibiting a very high reversible discharge capacity (2745 mA h g−1 at 200 mA g−1) and a fast charge and discharge capability (884 mA h g−1 at 3200 mA g−1), which is much higher than the conventional SNWAs (c-SNWAs, only 127 mA h g−1 at 3200 mA g−1). Meanwhile, they deliver an improved cycling stability (2178 mA h g−1 at 400 mA g−1 after 50 cycles). More significantly, the as-synthesized n-SNWAs on Cu foam also possess a superior specific areal capacity of 4.1 mA h cm−2 at 0.6 mA cm−2. Such excellent electrochemical performance is superior, or at least comparable, to the best report for Si anode materials. Combining the cost-effective and facile preparation method, the present n-SNWAs on Cu foam can serve as a promising anode for LIBs.
Co-reporter:Junchao Huo, Yanjie Hu, Hao Jiang and Chunzhong Li
Nanoscale 2014 vol. 6(Issue 15) pp:9078-9084
Publication Date(Web):09 Jun 2014
DOI:10.1039/C4NR00972J
A novel one-step, vapor-fed aerosol flame synthetic process (VAFS) has been developed to prepare Ti3+ self-doped titanium dioxide (TiO2). The freshly formed TiO2 was in situ surface hydrogenated during the condensation stage by introducing H2 above the flame, and Ti3+ ions were created near the surface of TiO2. The relative content of Ti3+ ions near the surface of TiO2 is estimated to be 8%. Because of the high absorption of visible light and suppression of charge recombination, the photocurrent density and decomposition of MB under visible light irradiation were remarkably enhanced. This study demonstrates a simple, potential method to produce Ti3+ self-doped TiO2 with effective photoactivity in visible light.
Co-reporter:Peng Zhao, Jing Zhang, Yihua Zhu, Xiaoling Yang, Xin Jiang, Yuan Yuan, Changsheng Liu and Chunzhong Li
Journal of Materials Chemistry A 2014 vol. 2(Issue 47) pp:8372-8377
Publication Date(Web):03 Oct 2014
DOI:10.1039/C4TB01445F
A highly efficient multifunctional nanoplatform for dual-modal luminescence imaging and pH-responsive drug delivery has been developed on the basis of a facile and novel strategy by covalently binding up-conversion (UC) luminescent NaYF4:Yb,Er nanoparticles with down-conversion (DC) fluorescent AgInS2–ZnS quantum dots. Due to the enriched carboxylic groups in the polymer shell of UC nanoparticles, the as-prepared nanocomposites (NCs) are water-soluble, functionalizable and able to load anti-cancer drug molecules, doxorubicin (DOX), by simple physical adsorption. The release of DOX from NCs was controlled by varying the pH, with an increased drug dissociation rate in an acidic environment, favorable for controlled drug release. Moreover, the endocytosis and the efficient drug release properties of the system were confirmed by luminescence microscopy. Hence, this approach provides a valuable method for fabricating a NC system with highly integrated functionalities for dual-modal luminescence cell imaging and targeted cancer therapy.
Co-reporter:Weina Chen, Hao Jiang, Yanjie Hu, Yihui Dai and Chunzhong Li
Chemical Communications 2014 vol. 50(Issue 64) pp:8856-8859
Publication Date(Web):16 Jun 2014
DOI:10.1039/C4CC02886D
Mesoporous single crystals Li4Ti5O12 grown on reduced graphene oxide (MSCs-LTO–rGO) nanohybrids have been synthesized by a simple hydrothermal reaction of TiO2/rGO and LiOH with subsequent annealing in Ar at 600 °C, which exhibited high specific capacity (171 mA h g−1) with much improved rate capability (132 mA h g−1 at 40 C) and intriguing cycling stability (85% capacity retention after 2000 cycles).
Co-reporter:Qi Yue, Hao Jiang, Yanjie Hu, Guiqi Jia and Chunzhong Li
Chemical Communications 2014 vol. 50(Issue 87) pp:13362-13365
Publication Date(Web):11 Sep 2014
DOI:10.1039/C4CC06733A
Mesoporous single-crystalline V2O5 nanorods assembled into novel hollow microspheres have been synthesized as cathode materials for lithium-ion batteries by a simple solvothermal treatment of NH4VO3 and ethylene glycol with subsequent annealing in air at 400 °C, which delivered a very high reversible capacity of 145.8 mA h g−1 at 2.5–4.0 V (vs. theoretical value: 147 mA h g−1) with much improved capacity retention and long cycle life at various rates.
Co-reporter:Jianfei Huang, Yihua Zhu, Hua Zhong, Xiaoling Yang, and Chunzhong Li
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 10) pp:7055
Publication Date(Web):May 6, 2014
DOI:10.1021/am501799w
A finely dispersed CuO nanoparticle electrocatalyst on a silicon nanowire (SiNW) was achieved via a designed, precursor-mediated strategy by combining metal-assisted chemical etching, electroless deposition, and thermal oxidation. The CuO assembled on silicon nanowires (CuO-SiNWs) showed a competent sensitivity of 22.27 μA/mM, a wider linear range from 0.01 to 13.18 mM, and a comparable detection limit of 1.6 μM (3S/N) for nonenzymatic H2O2 detection. The archetype sensor also demonstrated eligible selectivity against common interfering species. By the introduction of the SiNW carrier, which led to mitigated conglomeration of the electrocatalyst and a favorable microstructure of the electrocatalyst–carrier system, improved signal-concentration linearity and higher electrocatalyst utilization efficiency were obtained with CuO-SiNWs. These results demonstrated the feasibility of the synthetic strategy and the potential of the nanocomposite as a promising candidate for H2O2 sensing.Keywords: cupric oxide; hydrogen peroxide; mitigated conglomeration; nonenzymatic sensor; precursor-mediated; silicon nanowire;
Co-reporter:Yao Fu, Hao Jiang, Yanjie Hu, Ling Zhang, Chunzhong Li
Journal of Power Sources 2014 Volume 261() pp:306-310
Publication Date(Web):1 September 2014
DOI:10.1016/j.jpowsour.2014.03.005
•Hierarchical porous Li4Mn5O12 nano/micro structure has been synthesized.•The unique structure has the advantages of both nanostructure and microstructure.•The Li4Mn5O12 cathode exhibits excellent electrochemical performances for LIBs.To overcome the disproportionation reaction and Jahn-Teller distortion of Mn3+ in LiMn2O4 cathode materials, we demonstrate a facile route to synthesize hierarchical porous Li4Mn5O12 nano/micro structure, which consists of numerous well-crystallized nanoparticles with diameters of 20–30 nm. The unique structure combines the advantages of both nanostructure and microstructure. When applied as cathode materials for Li-ion batteries, it exhibited a very high specific capacity of 161 mAh g−1 (theoretical value: 163 mAh g−1) with intriguing rate performance and cycling stability.
Co-reporter:Hao Jiang, Yihui Dai, Yanjie Hu, Weina Chen, and Chunzhong Li
ACS Sustainable Chemistry & Engineering 2014 Volume 2(Issue 1) pp:70
Publication Date(Web):October 24, 2013
DOI:10.1021/sc400313y
A three-dimensional (3D) nanostructure comprised of ternary rGO/CNTs/MnO2 nanocomposites was successfully developed and prepared for high-rate supercapacitors. The optimized nanocomposite exhibited a high specific capacitance (SC) of 319 F g–1 with enhanced rate capability (222 F g–1 even at 60 A g–1) and cycling stability (85.4% retention of original capacity after cycling for 3000 times) in a 1 M Na2SO4 aqueous solution. Such outstanding capacitive behaviors are mainly attributed to smart nanostructures, which possess several advantages as supercapacitor electrodes, such as easy access pseudoactive species with high utilization and fast ion/electron transfer and also a strong interaction between the 3D rGO/CNTs carbon matrix and pseudoactive MnO2 nanoflakes. It is concluded that the present 3D rGO/CNTs/MnO2 nanocomposites can serve as promising electrode materials for advanced supercapacitors.Keywords: Carbon nanotubes; MnO2; Nanocomposite; Reduced graphene oxide; Supercapacitor
Co-reporter:Xiaoming Lv, Yihua Zhu, Hongliang Jiang, Hua Zhong, Xiaoling Yang and Chunzhong Li
Dalton Transactions 2014 vol. 43(Issue 40) pp:15111-15118
Publication Date(Web):13 Aug 2014
DOI:10.1039/C4DT02245A
A novel and facile strategy has been successfully developed to synthesize uniform gold@titanium dioxide octahedral nanocages (Au@TiO2), which have a well-defined double-shelled structure with Au as the internal shell and TiO2 as the external shell. The unique Au@TiO2 double-shelled octahedral nanocages were elaborately fabricated by a Cu2O-templated strategy combining with spatially confined galvanic replacement. The formation process of these delicate hierarchical octahedral architectures is discussed in detail. The catalytic performance of the Au@TiO2 double-shelled octahedral nanocages was investigated using the reduction of 4-nitrophenol as a model reaction. The mesoporous structure of both the Au and TiO2 shells provides direct access for the reactant molecules to diffuse and subsequently interact with the Au shell. This novel catalyst shows excellent and stable activity for the catalytic reduction of 4-nitrophenol, which can be recycled for ten successive cycles of the reaction with a conversion efficiency of more than 90%. The superior catalytic activity attributes to mesoporous double shells, enhanced synergistic effects between the Au and TiO2 shells and the unique properties of the octahedral structure. More importantly, the as-obtained Au@TiO2 double-shelled octahedral nanocages also show potential applications in solar cells, organocatalysis and water splitting.
Co-reporter:Xiaofang Han, Ling Zhang and Chunzhong Li
RSC Advances 2014 vol. 4(Issue 58) pp:30536-30541
Publication Date(Web):17 Jun 2014
DOI:10.1039/C4RA04182H
In the present study, we report a simple solution mixing method to prepare polydopamine-functionalized graphene–Fe3O4 (DGF) nanocomposites with high adsorption capacities and an easy-separation ability. Water-soluble Fe3O4 particles are firmly deposited onto the surfaces of graphene oxide (GO) via electrostatic and hydrogen interactions. The interaction between the GO and Fe3O4 particles can prevent the graphene nanosheets from restacking and the Fe3O4 particles from agglomeration. The introduction of dopamine to functionalize GO not only reduces the GO but also endows abundant chemical groups. The existence of polydopamine affords more active sites for adsorption and further enhances the interaction of the GO and Fe3O4 particles to obtain adsorbent materials with stable structures. The adsorption capacity of DGF nanocomposites for methylene blue (MB) is 365.39 mg g−1, which is much higher than that of graphene–Fe3O4 (GF) nanocomposite. Simultaneously, the DGF nanocomposites can be easily removed from polluted water after adsorption for MB by using a magnetic field, which is highly important for water conservation.
Co-reporter:Yanjie Hu, Hao Jiang, Jie Liu, Yunfeng Li, Xiaoyu Hou and Chunzhong Li
RSC Advances 2014 vol. 4(Issue 7) pp:3162-3164
Publication Date(Web):04 Nov 2013
DOI:10.1039/C3RA40998H
We demonstrated a large-scale, low-cost and rapid flame synthesis of hydrophobic magnetic chain-like nanoparticles (HMCNPs) composed of core–shell Fe2O3@SiO2 nanoparticles. The liquid marble made up of HMCNPs is highly compressible with rapid self-recovering ability mainly due to the intriguing elastic behavior and magnetic performance.
Co-reporter:Shilong Jing, Feng Gu, Junhua Kong, Chunrong Ma, Pooi See Lee and Chunzhong Li
RSC Advances 2014 vol. 4(Issue 21) pp:10450-10453
Publication Date(Web):11 Feb 2014
DOI:10.1039/C4RA00690A
We have developed hierarchical double-shelled SnO2 hollow spheres by a sequential template-engaged method, in which the loosened SnO2 floccules are well-grown on the inside wall of the hollow spheres. The unique hierarchical structure could provide more active sites for Li–Sn alloying–dealloying reaction and fast insertion/extraction of Li+ ion with superb conductivity, helping to store more lithium (2578 mA h g−1) with great cycling stability.
Co-reporter:Dayong Ren, Hao Jiang, Yanjie Hu, Ling Zhang and Chunzhong Li
RSC Advances 2014 vol. 4(Issue 76) pp:40368-40372
Publication Date(Web):22 Aug 2014
DOI:10.1039/C4RA08604J
We demonstrate the self-assembly of few-layer MoS2 nanosheets on a CNT backbone via a facile hydrothermal reaction with a subsequent annealing process. In this structure, the few-layer MoS2 nanosheets with controllable contents are alternately and vertically grown on the surface of CNTs, forming a three-dimensional hierarchical nanostructure. The optimized MoS2/CNTs hybrids could be applied as a fascinating anode material for high-rate and long cycle life lithium ion batteries (LIBs). Compared with the commercial MoS2 (716 mA h g−1), the as-prepared MoS2/CNTs hybrids exhibit a much higher specific capacity of 1293 mA h g−1 at 200 mA g−1 with remarkably enhanced rate capability (888 mA h g−1 even at 3200 mA g−1). More significantly, we find that the MoS2/CNTs hybrids show no capacity fading after 200 cycles at 400 mA g−1. As for MoS2-based anode materials, such overwhelming electrochemical performance endows the present MoS2/CNTs hybrids with huge potential for developing LIBs.
Co-reporter:Yihui Dai, Hao Jiang, Yanjie Hu, Yao Fu, and Chunzhong Li
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 8) pp:3125
Publication Date(Web):February 4, 2014
DOI:10.1021/ie403950t
Ultrathin, uniform and monodisperse hollow mesoporous carbon nanospheres (HMCNs) with a thickness of ∼3.8 nm have been synthesized. The obtained HMCNs have a high specific surface area (568 m2 g–1), large pore volume (1.63 cm3 g–1), and highly accessible mesopores (∼9.1 nm). Notably, we realized precise control of the shell thickness in the range of ultrathin size (<10 nm). When applied as supercapacitor electrodes, the HMCNs demonstrate impressive capacitive properties, such as high specific capacitance (253 F g–1), excellent rate capability (111 F g–1 at 60 A g–1) and outstanding cycling stability (only 3.8% loss after 5000 cycles). The results suggest that the unique structure of HMCNs can allow high rate electrolyte infiltration and rapid ion diffusion. The present findings push forward the development of carbon materials, exhibiting huge potential for applications in energy storage fields.
Co-reporter:Hao Jiang, Yanjie Hu, Shaojun Guo, Chaoyi Yan, Pooi See Lee, and Chunzhong Li
ACS Nano 2014 Volume 8(Issue 6) pp:6038
Publication Date(Web):May 14, 2014
DOI:10.1021/nn501310n
Searching the long-life MnO-based materials for lithium ion batteries (LIBs) is still a great challenge because of the issue related to the volumetric expansion of MnO nanoparticles (NPs) or nanowires (NWs) during lithiation. Herein, we demonstrate an unexpected result that a peapod-like MnO/C heterostructure with internal void space can be facilely prepared by annealing the MnO precursor (MnO-P) NW/polydopamine core/shell nanostructure in an inert gas, which is very different from the preparation of typical MnO/C core/shell NWs through annealing MnO NW/C precursor nanostructure. Such peapod-like MnO/C heterostructure with internal void space is highly particular for high-performance LIBs, which can address all the issues related to MnO dissolution, conversion, aggregation and volumetric expansion during the Li+ insertion/extraction. They are highly stable anode material for LIBs with a very high reversible capacity (as high as 1119 mAh g–1 at even 500 mA g–1) and fast charge and discharge capability (463 mAh g–1 at 5000 mA g–1), which is much better than MnO NWs (38 mAh g–1 at 5000 mA g–1) and MnO/C core/shell NWs (289 mAh g–1 at 5000 mA g–1). Such nanopeapods also show excellent rate capability (charged to 91.6% in 10.6 min using the constant current mode). Most importantly, we found that MnO/C nanopeapods show no capacity fading even after 1000 cycles at a high current density of 2000 mA g–1, and no morphology change. The present MnO/C nanopeapods are the most efficient MnO-based anode materials ever reported for LIBs.Keywords: anode material; heterostructure; lithium ion battery; MnO nanowire; nanopeapod
Co-reporter:Dr. Hongliang Jiang; Yihua Zhu;Dr. Qian Feng;Dr. Yunhe Su; Xiaoling Yang ; Chunzhong Li
Chemistry - A European Journal 2014 Volume 20( Issue 11) pp:3106-3112
Publication Date(Web):
DOI:10.1002/chem.201304561
Abstract
Despite tremendous progress in developing doped carbocatalysts for the oxygen reduction reaction (ORR), the ORR activity of current metal-free carbocatalysts is still inferior to that of conventional Pt/C catalysts, especially in acidic media and neutral solution. Moreover, it also remains a challenge to develop an effective and scalable method for the synthesis of metal-free carbocatalysts. Herein, we have developed nitrogen and phosphorus dual-doped hierarchical porous carbon foams (HP-NPCs) as efficient metal-free electrocatalysts for ORR. The HP-NPCs were prepared for the first time by copyrolyzing nitrogen- and phosphorus-containing precursors and poly(vinyl alcohol)/polystyrene (PVA/PS) hydrogel composites as in situ templates. Remarkably, the resulting HP-NPCs possess controllable nitrogen and phosphorus content, high surface area, and a hierarchical interconnected macro-/mesoporous structure. In studying the effects of the HP-NPCs on the ORR, we found that the as-prepared HP-NPC materials exhibited not only excellent catalytic activity for ORR in basic, neutral, and acidic media, but also much better tolerance for methanol oxidation and much higher stability than the commercial, state-of-the-art Pt/C catalysts. Because of all these outstanding features, it is expected that the HP-NPC material will be a very suitable catalyst for next-generation fuel cells and lithium–air batteries. In addition, the novel synthetic method described here might be extended to the preparation of many other kinds of hierarchical porous carbon materials or porous carbon that contains metal oxide for wide applications including energy storage, catalysis, and electrocatalysis.
Co-reporter:Hao Jiang, Pooi See Lee and Chunzhong Li
Energy & Environmental Science 2013 vol. 6(Issue 1) pp:41-53
Publication Date(Web):12 Oct 2012
DOI:10.1039/C2EE23284G
Supercapacitors have attracted intense attention due to their great potential to meet the demand of both high energy density and power density in many advanced technologies. Various carbon-based nanocomposites are currently pursued as supercapacitor electrodes because of the synergistic effect between carbon (high power density) and pseudo-capacitive nanomaterials (high energy density). This feature article aims to review most recent progress on 3D (3D) carbon based nanostructures for advanced supercapacitor applications in view of their structural intertwinement which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The carbon nanostructures comprise of CNTs-based networks, graphene-based architectures, hierarchical porous carbon-based nanostructures and other even more complex carbon-based 3D configurations. Their advantages and disadvantages are compared and summarized based on the results published in the literature. In addition, we also discuss and view the ongoing trends in materials development for advanced supercapacitors.
Co-reporter:Xiaoyu Hou, Yanjie Hu, Hao Jiang, Junchao Huo, Yunfeng Li and Chunzhong Li
Journal of Materials Chemistry A 2013 vol. 1(Issue 44) pp:13814-13820
Publication Date(Web):10 Sep 2013
DOI:10.1039/C3TA12533E
Branch-type SnO2 nanowires with high crystallinity have been successfully prepared by a rapid and continuous flame spray pyrolysis (FSP) route. The SnO2 branch has an average diameter of 15–20 nm and a length of 200–700 nm. As is known, this is the first time one dimensional SnO2 nanowires with branch-type nanostructures have been synthesized using flame synthesis. The average growth rate of nanowires could reach 1 μm s−1, which is thousand times faster than other methods. Interestingly, it is found that Au nanoclusters appear at the tip of SnO2 nanowires. An in situ Au-catalyzed vapour–liquid–solid (VLS) model is proposed to explain the growth mechanism of branch-type SnO2 nanowires in flame. As photoanodes, the DSSCs based on branch-type SnO2 nanowires (with TiCl4 post-treatment) show a higher short-circuit current (JSC = 10.60 mA cm−2) and a superior power conversion efficiency of 4.23%, improved by 99.5% compared to pure SnO2 nanoparticles (2.12%). The efficiency improvement could be attributed to the unique branch-type nanowire architecture, which provides a highly efficient electron channel and excellent ability of light scattering.
Co-reporter:Yunfeng Li, Yanjie Hu, Hao Jiang and Chunzhong Li
Nanoscale 2013 vol. 5(Issue 12) pp:5360-5367
Publication Date(Web):02 Apr 2013
DOI:10.1039/C3NR01087B
Double-faced γ-Fe2O3||SiO2 nanohybrids (NHs) and their in situ selective modification on silica faces with the 3-methacryloxypropyltrimethoxysilane molecules have been successfully prepared by a simple, rapid and scalable flame aerosol route. The double-faced NHs perfectly integrate magnetic hematite hemispheres and non-magnetic silica parts into an almost intact nanoparticle as a result of phase segregation during the preparation process. The unique feature allows us to easily manipulate these particles into one-dimensional chain-like nanostructures. On the other hand, in situ selectively modified double-faced γ-Fe2O3||SiO2 NHs possess excellent interfacial activities, which can assemble into many interesting architectures, such as interfacial film, magnetic responsive capsules, novel magnetic liquid marbles and so forth. The modified NHs prefer to assemble at the interface of water–oil or oil–water systems. It is believed that the highly interfacial active NHs are not only beneficial for the development of interface reaction in a miniature reactor, but also very promising functional materials for other smart applications.
Co-reporter:Mengting Chen, Tao Tao, Ling Zhang, Wei Gao and Chunzhong Li
Chemical Communications 2013 vol. 49(Issue 16) pp:1612-1614
Publication Date(Web):04 Jan 2013
DOI:10.1039/C2CC38290C
We have manufactured a highly conductive and stretchable composite by backfilling a preformed graphene/MWCNT aerogel with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 2.8 S cm−1 with only 1.3 wt% graphene/MWCNT loading, and remains constant after 100 times repeated stretching by 20% and 5000 times bending.
Co-reporter:Xiaoyu Hou, Hao Jiang, Yanjie Hu, Yunfeng Li, Junchao Huo, and Chunzhong Li
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 14) pp:6672
Publication Date(Web):June 18, 2013
DOI:10.1021/am401442v
In this paper, we have demonstrated a hierarchical architecture assembly from Sn-filled CNTs, which was in situ deposited on Cu foils to form binder-free electrode by incorporating flame aerosol deposition (FAD) with chemical vapor deposition (CVD) processes. The reversible capacity of Sn-filled CNTs hierarchical architecture anode exhibited above 1000 mA h g–1 before 30th cycle and stabilized at 437 mA h g–1 after 100 cycles at a current density of 100 mA g–1. Even at as high as 2 A g–1, the capacity still maintained 429 mA h g–1. The desirable cycling life and rate capacities performance were attributed to great confinement of tin in the interior of CNTs and the superior conducting network constructed by the 3D hierarchical architecture. The novel, rapid and scalable synthetic route was designed to prepare binder-free electrode with high electrochemical performance and avoid long-time mixing of active materials, binder, and carbon black, which is expected to be one of promising preparation of Sn/C anodes in lithium-ion batteries.Keywords: binder-free electrode; deposition; flame synthesis; hierarchical architecture; lithium-ion batteries; Sn-filled CNTs;
Co-reporter:Yanjie Hu, Yunli Shi, Hao Jiang, Guangjian Huang, and Chunzhong Li
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 21) pp:10643
Publication Date(Web):October 11, 2013
DOI:10.1021/am402604h
Silica-coated Ag nanoparticles (Ag@SiO2 NPs) have been successfully prepared by a scalable flame spray pyrolysis (FSP) technique with production rate up to 4 g/h in laboratory-scale. The ultrathin SiO2 shell, with a thickness 1 nm, not only effectively avoids the intersintering of Ag nanoparticles core at the high temperature, but also serves as a protective layer of the SERS-active nanostructure. The silica-coated Ag nanoparticles form agglomerates in the large temperature gradient zone, which with several nanometers gaps from each other but not contact. Such an intriguing feature can result in more Raman hot-spots generated at the gaps among Ag core active sites, which will beneficial for the whole SERS substrate enhancement. The results demonstrate that a maximum enhancement factor can reach ∼105 with a detectable concentration as low as 10–10 M for rhodamine 6G (R6G) molecules, indicating that the as-obtained unique nanostructure will be a promising candidate for SERS applications.Keywords: Ag@SiO2 NPs; FSP; SERS; ultrathin silica-coated;
Co-reporter:Yunfeng Li, Yanjie Hu, Hao Jiang, Xiaoyu Hou and Chunzhong Li
CrystEngComm 2013 vol. 15(Issue 34) pp:6715-6721
Publication Date(Web):12 Jun 2013
DOI:10.1039/C3CE40737C
In this paper, novel core–shell α-Fe2O3/SnO2 heterostructures (HSs) are successfully prepared by a one-step flame-assisted spray copyrolysis of iron and tin precursor. The effect of SnO2 component is investigated for the evolution of phase composition and morphology in detail. For the first time, it is noted that SnO2 as a dopant can effectively promote the phase transition of γ-Fe2O3 to α-Fe2O3 during flame synthesis. A phase-segregation induced growth mechanism is proposed to explain the formation of a unique core–shell structure. Such core–shell HSs as LIB anode materials exhibit an enhanced lithium storage capacity in comparison to pure Fe2O3 and SnO2. This enhancement could be ascribed to the synergetic effect of both single components as well as the unique core–shell HSs.
Co-reporter:Jingping Ma, Qilin Cheng, Vladimir Pavlinek, Petr Saha and Chunzhong Li
New Journal of Chemistry 2013 vol. 37(Issue 3) pp:722-728
Publication Date(Web):18 Dec 2012
DOI:10.1039/C2NJ40880E
Uniform MnO2 hollow nanospheres with hierarchical (urchin-like and flower-like) and non-hierarchical structures have been synthesized via a dual-template assisted hydrothermal process. The morphology control of the MnO2 hollow spheres can be easily achieved by altering the mass ratio of Pluronic F-127 to silica spheres. Material characterizations reveal that urchin-like hollow spheres possess the highest BET surface area of 233.4 m2 g−1 among the diverse morphologies. A possible formation mechanism for the MnO2 hollow spheres with different morphologies is proposed. The supercapacitive performance of the MnO2 spheres was investigated by cyclic voltammetry and galvanostatic charge–discharge techniques. The urchin-like hollow spheres exhibit the highest specific capacitance of 266.6 F g−1 within the potential range of 0–1.0 V. The relationship between the specific capacitance and the morphology of the MnO2 hollow spheres is also discussed. The good capacitive behavior and cycling stability of the hierarchical MnO2 hollow spheres highlights the importance of the morphological design and control of materials in practical supercapacitor applications.
Co-reporter:Tao Tao, Ling Zhang, Hao Jiang and Chunzhong Li
New Journal of Chemistry 2013 vol. 37(Issue 5) pp:1294-1297
Publication Date(Web):06 Mar 2013
DOI:10.1039/C3NJ00159H
We demonstrated a facile route to realize the synthesis of a functional mesoporous carbon-coated CNT network, which exhibited a high specific capacitance of 214 F g−1 at 10 mV s−1 with intriguing rate and stability due to the synergistic effect between them.
Co-reporter:Junchao Huo, Yanjie Hu, Hao Jiang, Wenjuan Huang, Yunfeng Li, Wei Shao, and Chunzhong Li
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 32) pp:11029
Publication Date(Web):July 17, 2013
DOI:10.1021/ie4006222
A novel one-step and template-free preparation process had been developed to synthesize TiO2 hierarchically porous hollow spheres (HPHSs) by mixed solvents assisted flame spray pyrolysis (FSP). The as-obtained TiO2 HPHSs had hierarchically porous hollow structure such as central cavities, macropores on shells, and mesopores accumulated by TiO2 nanocrystallites. The unique hierarchically porous structure endowed the TiO2 spheres with high specific surface area and excellent light scattering property. A mechanism of the formation of TiO2 HPHSs depending on the competition between chemical reaction rate and diffusion rate of the components of the precursor was proposed, in which mixed solvents and short flame residence time were of importance. Furthermore, the dye-sensitized solar cells (DSSCs) performance of TiO2 HPHSs as light scattering layer was investigated. The photoelectric conversion efficiency (η) was improved by 38.2% (from 5.00% to 6.91%), comparing to that of single layer P25 films.
Co-reporter:Yihui Dai, Hao Jiang, Yanjie Hu and Chunzhong Li
RSC Advances 2013 vol. 3(Issue 43) pp:19778-19781
Publication Date(Web):16 Aug 2013
DOI:10.1039/C3RA42664E
Novel Mn2O3 hollow nanocones have been successfully prepared as a lithium ion batteries anode material by a hydrothermal then annealing process, which exhibited a high specific capacity of ∼900 mA h g−1 at 50 mA g−1 with intriguing rate performance and cycling stability.
Co-reporter:Yunfeng Li, Yanjie Hu, Guangjian Huang, Chunzhong Li
Particuology 2013 Volume 11(Issue 4) pp:460-467
Publication Date(Web):August 2013
DOI:10.1016/j.partic.2012.10.008
•Core–shell metallic Fe nanoparticles were synthesized via flame spray pyrolysis.•Iron core and Fe3O4 shell were obtained via tailoring residence time and atmosphere in flame.•Formation of metallic Fe in flame may be attributed to strong reducing atmosphere.•Competition mechanism between reducing and oxidizing flames were proposed.Metallic iron (Fe) nanoparticles (NPs) with a typical core–shell structure have been prepared by a simple and continuous flame spray pyrolysis (FSP) method, which are stabilized by the corresponding Fe3O4 shell with a thickness of 4–6 nm. The size of metallic Fe cores is about 30–80 nm. The core–shell structured iron NPs show an air stability as long as one month as a result of the protection of oxide shell. Through the control of the residence time of materials in flame and flame atmosphere, metallic Fe and iron oxides are obtained, showing a better external magnetic field responsibility. It is concluded that the evolution of morphology and composition of flame-made magnetic NPs could be attributed to the competition mechanism between reduction and oxidation reactions of in situ flame combustion, which offers more choices and better effective design strategy for the synthesis of advanced functional materials via FSP techniques.
Co-reporter:Hao Jiang, Jan Ma and Chunzhong Li
Journal of Materials Chemistry A 2012 vol. 22(Issue 33) pp:16939-16942
Publication Date(Web):27 Jun 2012
DOI:10.1039/C2JM33249C
We demonstrated the facile loading of ultrafine and loosened K-birnessite MnO2 floccules on the surface of polyaniline (PANI) nanofibers by simply soaking the polyaniline nanofibers in a KMnO4 aqueous solution for electrochemical energy storage applications. The as-prepared PANI–MnO2 coaxial nanofibers with optimal composition, when applied as an electrode, exhibited a high specific capacitance (383 F g−1 at 0.5 A g−1) with good rate and cycling stability in 1 M Na2SO4 aqueous solution. Such intriguing electrochemical performance is mainly attributed to the synergistic effects of the combined pseudo-capacitive contributions from the core and shell. The present findings promoted the development of advanced electrode materials, exhibiting huge potential for supercapacitors.
Co-reporter:Hao Jiang, Chunzhong Li, Ting Sun and Jan Ma
Nanoscale 2012 vol. 4(Issue 3) pp:807-812
Publication Date(Web):12 Dec 2011
DOI:10.1039/C1NR11542A
A green asymmetric supercapacitor with high energy density has been developed using birnessite-type ultrathin porous MnO2 nanoflowers (UBMNFs) as positive electrode and functional mesoporous carbon nanotubes (FMCNTs) as negative electrode in 1 M Na2SO4 electrolyte. Both of the electrode materials possess excellent electrochemical performances, with high surface areas and narrow pore size distributions. More significantly, the assembled asymmetric supercapacitor with optimal mass ratio can be cycled reversibly in the high-potential range of 0–2.0 V and exhibits an excellent energy density as high as 47.4 W h kg−1, which is much higher than those of symmetric supercapacitors based on UBMNFs//UBMNFs and FMCNTs//FMCNTs supercapacitors. Furthermore, our asymmetric supercapacitor (ASC) device also exhibits a superior cycling stability with 90% retention of the initial specific capacitance after 1000 cycles and stable Coulombic efficiency of ∼98%. These intriguing results exhibit great potential in developing high energy density “green supercapacitors” for practical applications.
Co-reporter:Jianhua Shen, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Journal of Materials Chemistry A 2012 vol. 22(Issue 26) pp:13341-13347
Publication Date(Web):16 May 2012
DOI:10.1039/C2JM31998E
We have demonstrated a sandwich-structured Fe3O4/SiO2/Au/TiO2 photocatalyst, which shows magnetic separability, selective absorption and photocatalysis activity, and high efficiency, in catalyzing the decomposition of organic compounds under illumination of visible-light and simulated sunlight. The structural design of the photocatalyst takes advantage of the dense, homogeneous structure and the AuNPs content (ca. 4 nm, 1.63 wt%), which is prepared by a simple method. It possesses high efficiency visible-light photocatalytic activity due to the stable from nonmetal-doping and the plasmonic metal decoration, which enhances light harvesting and charge separation, and the small grain size of the anatase nanocrystals, which reduces the exciton recombination rate. More importantly, the catalyst is synthesized by a combination of plasmonic metal decoration of TiO2 nanocrystals with exposed {001} facets, and the selective adsorption and photocatalytic decomposition of azo dyes is accomplished by design of the surface chemistry. Additionally, these sandwich-structured photocatalysts can be applied to other catalytic system such as dye decoloration, water decomposition, hydrogen generation, and so on.
Co-reporter:Hao Jiang, Ting Sun, Chunzhong Li and Jan Ma
Journal of Materials Chemistry A 2012 vol. 22(Issue 6) pp:2751-2756
Publication Date(Web):16 Dec 2011
DOI:10.1039/C1JM14732C
Three kinds of hierarchical porous nanostructures assembled from ultrathin MnO2 nanoflakes with different sizes and crystallinities, have been synthesized by a very simple and scalable strategy. When applied as electrode materials for supercapacitors, all of them exhibited enhanced electrochemical performances due to the high utilization of active materials. More significantly, based on these ultrathin nanostructures, we have discussed the relationships between their specific areas, pore sizes and crystallinities and their electrochemical performances. Among them, the product synthesized in an ice bath with an especially high specific area (269 m2 g−1), uniform pore size distribution (∼5.1 nm) and poor crystallinity, exhibited the highest specific capacitance (328 F g−1) with a high rate and cycling stability. It is thought that the hierarchical ultrathin porous nanostructures can serve as promising electrode materials for supercapacitors.
Co-reporter:Hao Jiang, Jan Ma and Chunzhong Li
Chemical Communications 2012 vol. 48(Issue 37) pp:4465-4467
Publication Date(Web):19 Mar 2012
DOI:10.1039/C2CC31418E
We demonstrate a simple and scalable strategy for synthesizing hierarchical porous NiCo2O4 nanowires which exhibit a high specific capacitance of 743 F g−1 at 1 A g−1 with excellent rate performance (78.6% capacity retention at 40 A g−1) and cycling stability (only 6.2% loss after 3000 cycles).
Co-reporter:Hao Jiang, Chunzhong Li, Ting Sun and Jan Ma
Chemical Communications 2012 vol. 48(Issue 20) pp:2606-2608
Publication Date(Web):10 Jan 2012
DOI:10.1039/C2CC18079K
Ni(OH)2/MnO2 core–shell nanowires with a nanoflake surface have been designed and synthesized, and can be applied not only in neutral electrolytes (355 F g−1, 70.4 wt% MnO2) but are also appropriate for alkaline electrolytes (487.4 F g−1, 35.5 wt% MnO2), with high cycling stability due to the synergistic effect between the core and shell.
Co-reporter:Jianhua Shen, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Chemical Communications 2012 vol. 48(Issue 31) pp:3686-3699
Publication Date(Web):21 Feb 2012
DOI:10.1039/C2CC00110A
Similar to the popular older cousins, luminescent carbon dots (C-dots), graphene quantum dots or graphene quantum discs (GQDs) have generated enormous excitement because of their superiority in chemical inertness, biocompatibility and low toxicity. Besides, GQDs, consisting of a single atomic layer of nano-sized graphite, have the excellent performances of graphene, such as high surface area, large diameter and better surface grafting using π–π conjugation and surface groups. Because of the structure of graphene, GQDs have some other special physical properties. Therefore, studies on GQDs in aspects of chemistry, physical, materials, biology and interdisciplinary science have been in full flow in the past decade. In this Feature Article, recent developments in preparation of GQDs are discussed, focusing on the main two approaches (top-down and bottom-down). Emphasis is given to their future and potential development in bioimaging, electrochemical biosensors and catalysis, and specifically in photovoltaic devices that can solve increasingly serious energy problems.
Co-reporter:Yanfang Yan, Qilin Cheng, Vladimir Pavlinek, Petr Saha, Chunzhong Li
Electrochimica Acta 2012 Volume 71() pp:27-32
Publication Date(Web):1 June 2012
DOI:10.1016/j.electacta.2012.03.101
Polyaniline/mesoporous carbon/MnO2 (PANI/CMK-3/MnO2) ternary nanocomposites with a PANI nanolayer uniformly deposited on the CMK-3/MnO2 particles were synthesized by chemical oxidative polymerization. Structure and morphology of the ternary composites were further characterized by TEM, XRD, FTIR and FE-SEM techniques. Electrochemical measurements demonstrated that the ternary composite with 12% MnO2 content possessed enhanced specific capacitance of 695 F g−1 and the capacitance retention was 88% after 1000 galvanostatic charge-discharge cycles at a current density of 1.0 A g−1. The incorporation of MnO2 nanoparticles can not only contribute to high capacitance but also stabilize the interaction between the quinoid ring of PANI and the CMK-3/MnO2 particles. The PANI nanolayer in the ternary composite restrains the dissolution of MnO2 nanoparticles in acidic electrolyte so as to enhance their electrochemical utilization. The synergistic effect among three components may result in enhanced specific capacitance and cycling stability of the ternary composites.Highlights► A new polyaniline/mesoporous carbon/MnO2 (PANI/CMK-3/MnO2) ternary nanocomposite was synthesized via a simple approach. ► The ternary composite with 12% MnO2 content possesses enhanced specific capacitance of 695 F g−1 at 0.3 A g−1. ► The nanocomposite electrode exhibits outstanding rate performance and good cycling stability.
Co-reporter:Tao Tao, Ling Zhang, Jan Ma, and Chunzhong Li
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 15) pp:5456-5460
Publication Date(Web):March 23, 2012
DOI:10.1021/ie2008218
Polyethylene–multiwalled carbon nanotube shish-kebab (PE/MWCNT SK) structures with a large aspect ratio were synthesized by solvothermal growth followed by recrystallization. The effects of different crystallization temperatures (95, 105, and 115 °C) on the polymer were investigated, and the diameter of the PE crystal lamellae on the nanotubes was found to decrease with increasing crystallization temperature. Moreover, isothermal recrystallization of the SK structure at 115 °C produced crystal lamellae that were uniform in diameter, with dimensions that could be controlled by the recrystallization time. We studied also the stretchable electrical properties of uniform PE/MWCNT SK structures films on elastomer substrates under different strains. The electrical resistance of an SK/elastomer film was found to increase more slowly, compared to that of a film without the SK configuration, where an abrupt transition at a critical point was observed.
Co-reporter:Yunfeng Li, Yanjie Hu, Junchao Huo, Hao Jiang, Chunzhong Li, and Guangjian Huang
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 34) pp:11157-11162
Publication Date(Web):August 9, 2012
DOI:10.1021/ie3010644
Air stable Co3Fe7–CoFe2O4 nanoparticles have been synthesized via one-step flame spray pyrolysis of a mixture of Fe/Co precursor solution under stronger reducing atmosphere. The as-synthesized nanoparticles with diameters of 20–80 nm showed a typical core shell structure and high stability for being one month in air, whose metallic Co3Fe7 cores were protected against oxidation by a surface shell of about 2–4 nm cobalt iron oxide (CoFe2O4). The ratio of metallic Fe/Co alloy nanoparticles was 7:3. The alloy nanoparticles exhibited enhanced saturation magnetization (126.1 emu/g), compared with flame sprayed iron nanoparticles with the same conditions. The formation process of metallic alloy nanoparticles with core–shell structure was investigated, which included three stages: flame combustion, reducing, and surface oxidation during the flame process. It is reckoned that such a continuous production approach is an effective way to produce the stable Co3Fe7 alloy nanoparticles with high saturation magnetization.
Co-reporter:Lei Jin, Ling Zhang, Danhua Su, and Chunzhong Li
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 13) pp:4927-4933
Publication Date(Web):March 15, 2012
DOI:10.1021/ie202306v
We developed an approach to prepare the multilayered 3D composites where aligned multiwalled carbon nanotubes (MWCNTs) were grown on the surface of quartz fiber cloths (QFCs) by chemical vapor deposition method. The morphologies of the MWCNTs-QFCs preforms were analyzed by field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The results showed that the growth of high yield and uniform alignment of MWCNTs on the surface of QFCs could be controlled by the process. The unique MWCNTs-QFCs preforms, when served as connecting bridges for structural epoxy composites, demonstrated a significant enhancement of the interlaminar shear strength and electrical conductivity along in-plane and out-of-plane directions when compared to QFCs/epoxy composites without MWCNTs, making the MWCNTs-QFCs reinforcements meaningful in structural composites.
Co-reporter:Jun Jiang, Feng Gu, Wei Shao, and Chunzhong Li
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 7) pp:2838-2845
Publication Date(Web):January 13, 2012
DOI:10.1021/ie202049j
Spherical multihollow (MH) TiO2 nanostructures have been synthesized via a microemulsion-based approach with titanium glycerolate complexes formation at glycerol microemulsions interface. The self-aggregation of those microemulsions induces the formation of MH TiO2 nanospheres. Owing to this hierarchical hollow structure, photoanode films derived from MH TiO2 nanosphere as light scattering layer exhibits an enhanced light harvesting efficiency, thus leading to a 43% increment of photovoltaic performance compared to that from P25 nanoparticle film.
Co-reporter:Jianhua Shen, Yihua Zhu, Xiaoling Yang, Jie Zong, Jianmei Zhang and Chunzhong Li
New Journal of Chemistry 2012 vol. 36(Issue 1) pp:97-101
Publication Date(Web):25 Oct 2011
DOI:10.1039/C1NJ20658C
A novel and simple approach for preparing graphene quantum dots surface-passivated by polyethylene glycol (GQDs-PEG) has been developed by a one-pot hydrothermal reaction, using small graphene oxide (GO) sheets and polyethylene glycol (PEG) as starting materials. The prepared GQDs-PEG show excellent luminescence properties, the PL quantum yield of the GQDs-PEG with 360 nm emission was about 28.0%, which was two times higher than the pure GQDs. Interestingly, the GQDs-PEG possess the upconversion photoluminescence (UCPL) properties. Blue PL was clearly shown both under the ultraviolet and 808 nm laser in the fluorescent microscopy images. So the GQDs-PEG may provide a new type of fluorescence and upconversion material for applications in bioscience and energy technology. Especially, the GQDs-PEG showed higher photocurrent generation capability. And their photoelectrode generated an obvious and stable photocurrent under a 808 nm near-infrared (NIR) laser. Due to the low cost and simple method, GQDs-PEG thus provide a cost-effective dopant material for solar energy conversion.
Co-reporter:Hao Jiang, Liping Yang, Chunzhong Li, Chaoyi Yan, Pooi See Lee and Jan Ma
Energy & Environmental Science 2011 vol. 4(Issue 5) pp:1813-1819
Publication Date(Web):30 Mar 2011
DOI:10.1039/C1EE01032H
In this paper, using manganese oxide as an example, we report the successful design and synthesis of a novel one-dimensional highly graphitic carbon-tipped manganese oxide/mesoporous carbon/manganese oxide hybrid nanowire. The unique structure significantly improves the conductivity of metal oxide materials, which is a key limitation in pseudocapacitors. The hybrid nanowire with optimal carbon content, when applied as an electrode, exhibits superior capacitive properties in 1 M Na2SO4 aqueous solution, such as high specific capacitance (266 F g−1 at 1 A g−1), excellent rate capability (56.4% capacity retention at 60 A g−1) and outstanding cycling stability (without degradation after 1200 cycles). The energy densities achieved can be as high as 20.8 W h kg−1, at a power density of 30 kW kg−1. The results demonstrated that the manganese oxide in our hybrid nanomaterial was efficiently utilized with the assistance of the highly conductive graphitic carbon-tipped mesoporous carbon shell. It is reckoned that the present low-cost novel hybrid nanowire can serve as a promising electrode material for supercapacitors and other electrochemical devices.
Co-reporter:Xiao Hua Yang, Zhen Li, Chenghua Sun, Hua Gui Yang, and Chunzhong Li
Chemistry of Materials 2011 Volume 23(Issue 15) pp:3486
Publication Date(Web):July 11, 2011
DOI:10.1021/cm2008768
Due to its great importance in fundamental research and practical applications, tailored synthesis of anatase TiO2 dominated with highly energetic {001} facets has been extensively studied during the past few years. However, clean (001) surface of anatase TiO2 has been evidenced to be unstable and usually tends to reconstruct under ultrahigh-vacuum conditions. Thus, the stability of surface structure under other ambient conditions might be one of the most critical issues for anatase TiO2 with exposed high-reactive {001} facets. In this study, the hydrothermal stability of {001} faceted anatase TiO2 was systematically investigated by using single-crystalline anatase TiO2 nanosheets with 80% {001} facets as a model starting material. Under hydrothermal conditions (200 °C in deionized water), anatase TiO2 nanosheets can grow into larger single crystals with a truncated bipyramidal shape through an oriented attachment process along the [001] crystallographic direction, driven by the minimization of surface energy. Furthermore, the coarsening behavior and growth mechanism were discussed with the assistance of standard and high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectrometry, as well as theoretical calculations. A modified kinetic model was also developed to elucidate the asymptotic growth of anatase TiO2 nanosheets via oriented attachment mechanism. In addition, pH value and the solvents adopted during the treatments were revealed to have significant influence on the oriented attachment-based crystal growth due to suppression of hydrolysis of Ti–F groups on the surface. For example, the anatase TiO2 nanosheets remained their original morphology unchanged when ethanol, propanol, butanol, or 1.5 M HCl aqueous solution was used as reaction medium.Keywords: high-reactive facets; hydrothermal stability; nanosheets; oriented attachment; titanium dioxide;
Co-reporter:Hao Jiang, Ting Zhao, Chunzhong Li and Jan Ma
Journal of Materials Chemistry A 2011 vol. 21(Issue 11) pp:3818-3823
Publication Date(Web):2011/01/24
DOI:10.1039/C0JM03830J
Uniform Ni(OH)2 hierarchical nanostructures, assembled from ultrathin nanoflakes with thickness of only ∼7.4 nm, are designed and investigated as electrochemical pseudo-capacitor materials for potential energy storage applications. The ultrathin nanostructures exhibit a highest specific capacitance of 1715 F g−1 at a scan rate of 5 mV s−1 within the potential range of 0.6 V with high rate capability and good cycling stability. The high specific capacitance and remarkable rate capability are promising for supercapacitor applications. To understand the effect of the microstructure on the properties, we also synthesized uniformly stacked Ni(OH)2 nanoplatelets (thickness of ∼22 nm) and randomly arranged hexagonal nanosheets (thickness of ∼140 nm). Both of the latter configurations exhibited good performance despite showing inferior properties compared to the uniform ultrathin Ni(OH)2 nanostructures. These results suggest the importance of rational design and synthesis of ultrathin nanomaterials for high-performance energy applications.
Co-reporter:Jianhua Shen, Yihua Zhu, Cheng Chen, Xiaoling Yang and Chunzhong Li
Chemical Communications 2011 vol. 47(Issue 9) pp:2580-2582
Publication Date(Web):21 Dec 2010
DOI:10.1039/C0CC04812G
A facile hydrazine hydrate reduction of graphene oxide (GO) with surface-passivated by a polyethylene glycol (PEG) method for the fabrication of graphene quantum dots (GQDs) with frequency upconverted emission is presented. And we speculate on the upconversion luminescence due to the anti-Stokes photoluminescence (ASPL), where the δE between the π and σ orbitals is near 1.1 eV.
Co-reporter:Feng Gu, Lili Gai, Wei Shao, Chunzhong Li and Lukas Schmidt-Mende
Chemical Communications 2011 vol. 47(Issue 29) pp:8400-8402
Publication Date(Web):24 Jun 2011
DOI:10.1039/C1CC12309B
A seeded heteroepitaxial growth of ZnO nanorods selectively on TiO2 nanorod tips was achieved by restricting crystal growth on highly hydrophobic TiO2 nanorod film surfaces. Intriguing light harvesting performance and efficient charge transport efficiency has been found, which suggest potential applications in photovoltaics and optoelectronics.
Co-reporter:Hao Jiang, Ting Zhao, Chunzhong Li and Jan Ma
Chemical Communications 2011 vol. 47(Issue 30) pp:8590-8592
Publication Date(Web):27 Jun 2011
DOI:10.1039/C1CC12942B
Functional mesoporous carbon nanotubes (MCNTs) and their integration in situ with Pt nanocrystals (Pt/MCNTs) have been designed and successfully developed via a facile route, which exhibited enhanced performances in energy storage and conversion applications.
Co-reporter:Wei Shao, Feng Gu, Lili Gai and Chunzhong Li
Chemical Communications 2011 vol. 47(Issue 17) pp:5046-5048
Publication Date(Web):25 Mar 2011
DOI:10.1039/C1CC10548E
Hierarchical anatase TiO2 nanoplates with tunable shell structure were developed as the novel planar scattering layer in dye-sensitized solar cells, showing improved cell performance due to the enhanced light harvesting capability.
Co-reporter:Yanfang Yan, Qilin Cheng, Gengchao Wang, Chunzhong Li
Journal of Power Sources 2011 Volume 196(Issue 18) pp:7835-7840
Publication Date(Web):15 September 2011
DOI:10.1016/j.jpowsour.2011.03.088
Vertically aligned polyaniline nanowhiskers (PANI-NWs) doped with (1R)-(−)-10-Camphorsulfonic acid (L-CSA) have been successfully synthesized on the external surface of ordered mesoporous carbon (CMK-3) by chemical oxidative polymerization. The specific surface area of the PANI-NWs/CMK-3 nanocomposite remains as high as 497 m2 g−1 by removing mesoporous silica template after the polymerization of aniline. Structural and morphological characterizations of the nanocomposite were further investigated by XRD, FTIR and FE-SEM measurements. The result shows that the nanocomposite with 40 wt% PANI applying in supercapacitor devices possesses a large specific capacitance of 470 F g−1 and good capacitance retention of 90.4% is achieved after 1000 cycles at a current density of 1.0 A g−1. The synergistic effect of small PANI nanowhisker arrays and well-ordered mesoporous carbon endows the composite with high electrochemical capacitance and good cycling stability.Highlights► A facile approach to produce a novel nanocomposite with PANI nanowhiskers grown vertically on the outer surface of CMK-3 particles. ► The addition of CSA results in the formation of the PANI nanowhiskers on the CMK-3. ► The resulting nanocomposite retains ordered mesoporous structure and high surface area (497 m2 g−1). ► The nanocomposite electrode exhibits enhanced electrochemical performance and cycling stability.
Co-reporter:Xiao Hua Yang, Zhen Li, Gang Liu, Jun Xing, Chenghua Sun, Hua Gui Yang and Chunzhong Li
CrystEngComm 2011 vol. 13(Issue 5) pp:1378-1383
Publication Date(Web):12 Nov 2010
DOI:10.1039/C0CE00233J
Ultra-thin anatase TiO2 nanosheets with dominant {001} facets (∼82%) and controllable thickness (1.6–2.7 nm) were synthesized by using a modified one-pot hydrothermal route. As a morphology controlling agent, the concentration of hydrofluoric acid has a significant impact on the thickness of the as-synthesized TiO2 nanosheets. In addition, according to the XRD patterns and TEM images of the products on different reaction stages, the growth process of TiO2 nanosheets was clarified for the first time. We further measured the efficiency for H2 evolution of the ultra-thin anatase TiO2 nanosheets loaded with 1 wt% Pt from photochemical reduction of water in the presence of methanol as a scavenger. The TiO2 nanosheets exhibited a H2 evolution rate as high as 7381 μmol h−1 g−1 under UV-vis light irradiation, attributing to their exposed reactive {001} facets and high crystallinity.
Co-reporter:Jun Jiang, Feng Gu, Wei Shao, Lili Gai, Chunzhong Li and Guangjian Huang
CrystEngComm 2011 vol. 13(Issue 15) pp:4861-4865
Publication Date(Web):02 Jun 2011
DOI:10.1039/C1CE05180F
ZnO nanorods were helped to “stand” vertically on microsubstrates by an interesting seed-mediated approach. Taking ZnO nanosheets as the microsubstrates, ZnO nanorods can grow vertically, not lying horizontally, on the facets with the aid of a seed layer precoating to form hierarchical ZnO nanorod-nanosheet architectures. The diameter as well as the length of the standing nanorods can be controlled effectively by adjusting the growth time and ammonia amount in the growth solution. The precoated seed layer has been found to be the key factor in determining the resultant morphology. Room-temperature photoluminescence studies revealed that the near band-edge (NBE) emission intensity of the hierarchical architectures was increased greatly compared with that of bare ZnO nanosheets. These special hierarchical architectures make them appealing for future microdevice applications.
Co-reporter:Feng Gu, Xiang Ren, Jian Zhang, Wei Shao, Guangjian Huang, and Chunzhong Li
Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 22) pp:12542-12547
Publication Date(Web):October 5, 2011
DOI:10.1021/ie201152e
Morphological evolution from SnO2 quantum dots (QDs) to quantum chains (QCs) confined in channels of mesoporous silica (MS) has been studied systematically in this work by varying the nuclei quantity deposited on the channels’ inner surface under hydrothermal conditions. Decreasing the MS amounts could influence the nuclei quantity and the subsequent crystal growth as well as the assembly process to form QCs by oriented attachment inside the channels. It is interesting to find that the evolution of SnO2 QDs→QCs systems would induce the variation of strain type tolerated, simultaneously, from tensile to compressive strain, and also exhibit morphology-dependent photoluminescence properties.
Co-reporter:Jie Liu, Yanjie Hu, Feng Gu, Jan Ma, and Chunzhong Li
Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 9) pp:5584-5588
Publication Date(Web):April 7, 2011
DOI:10.1021/ie102244q
Premixed atmospheric flat flame deposition is a large-scale composite fabrication method that combined the advantages of flame synthesis and thermal evaporation. The technology has been successfully developed to sythesize SnO2 nanowires. The results showed that the as-prepared SnO2 nanowires with special tips are uniform single crystals, growing along [001] direction. Meanwhile, the growth mechanism of the present novel structure, which is a combination of both a vapor-solid (VS) growth mechanism and a particle formation mechanism in a flame without any catalyst, is also proposed. Furthermore, the optical property is investigated by photoluminescence (PL) spectroscopy, indicating that such SnO2 nanowires exhibit a much stronger emission peak at 620 nm. More importantly, this approach also provides a new pathway for sequentially engineering one-dimensional nanomaterials.
Co-reporter:Jun Jiang, Feng Gu, Xiang Ren, Yuhui Wang, Wei Shao, Chunzhong Li, and Guangjian Huang
Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 15) pp:9003-9008
Publication Date(Web):June 22, 2011
DOI:10.1021/ie200803q
A one-pot solvothermal approach has been developed for the synthesis of single-crystal anatase TiO2 nanospindles. The introduction of adscititious water in nonaqueous reaction mixture is critical for the spindle formation by allowing for a slow growth rate of TiO2 to facilitate the shape control of TiO2 nanospindles. Arising from the prominent light scattering effect, the fabricated dye sensitized solar cells with the TiO2 nanospindles as light scattering layer show a 27% increment of energy conversion efficiency compared to that of P25 single layer film.
Co-reporter:Xiao Hua Yang;Dr. Hua Gui Yang;Dr. Chunzhong Li
Chemistry - A European Journal 2011 Volume 17( Issue 24) pp:6615-6619
Publication Date(Web):
DOI:10.1002/chem.201100134
Co-reporter:Jie Zong, Yihua Zhu, Xiaoling Yang, Chunzhong Li
Materials Science and Engineering: C 2011 Volume 31(Issue 2) pp:166-172
Publication Date(Web):12 March 2011
DOI:10.1016/j.msec.2010.08.014
Monodispersed mesoporous silica spheres (MMSS) with controllable porosity and pore size were successfully prepared by calcination method in the presence of complex salts. The effect of calcination temperature on the pore size of MMSS was examined. The results show that the pore size of MMSS samples can be tuned in the range from 3.20 to 46.80 nm by varying the calcination temperature. It is worth mentioning that the pore size of MMSS can be controlled on a much larger scale by this method compared to the templating approach, by which the pore size can only be expanded up to 10 nm. It is very advantageous for the application in loading enzymes. Moreover, it could be found that the method is feasible, effective and simple. In addition, the use of various MMSS samples as adsorbents for Au nanoparticles of different sizes as well as urease has also been demonstrated. It was confirmed that MMSS with adequate surface charge and optimum matching pore size showed excellent adsorption properties for Au nanoparticles and urease.
Co-reporter:Junqing He;Ling Zhang ;Chunzhong Li
Polymer Engineering & Science 2011 Volume 51( Issue 5) pp:925-930
Publication Date(Web):
DOI:10.1002/pen.21915
Abstract
In this work, perfluoroalkylmethacrylate ester (PFAMAE)-grafted-linear low-density polyethylene (LLDPE) was synthesized by UV-induced surface graft polymerization. The effect of PFAMAE-grafted-LLDPE on the tribological behavior of LLDPE-filled polyoxymethylene (POM) composite was investigated using a friction and abrasion testing machine. The results showed that LLDPE-g-PFAMAE was a more effective modifier in improving tribological property of LLDPE-filled POM composite than conventional maleic anhydride-grafted-polyethylene (PE-g-MAH). POM/LLDPE composite possessed much lower friction coefficient but higher wear rate than pristine POM. The incorporation of LLDPE-g-PFAMAE into POM/LLDPE further decreased the friction coefficient, which was 45% lower than that of POM. The wear rate of POM/LLDPE/LLDPE-g-PFAMAE composite was also reduced and was lower than that of pristine POM. The primary wear mechanisms of POM/LLDPE composite with and without LLDPE-g-PFAMAE were adhesive and abrasive wear. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Co-reporter:Yujia Jing, Yihua Zhu, Xiaoling Yang, Jianhua Shen, and Chunzhong Li
Langmuir 2011 Volume 27(Issue 3) pp:1175-1180
Publication Date(Web):December 23, 2010
DOI:10.1021/la1042734
Multifunctional core−shell capsules that triggered release by ultrasound stimulus were one-step fabricated by the coaxial electrospray method. The TiO2 shell suppressed the initial burst release of the paclitaxel. Fe3O4 and graphene quantum dots inside the oil core functioned successfully for magnetic targeting and fluorescence imaging, respectively. Paclitaxel was trigger released when the dual layer of titania shell cracked under the ultrasound stimulation, and the releasing profile could be controlled by the length of applied ultrasound time.
Co-reporter:Jie Liu, Yanjie Hu, Feng Gu, Chunzhong Li
Particuology 2011 Volume 9(Issue 6) pp:632-636
Publication Date(Web):December 2011
DOI:10.1016/j.partic.2010.12.004
A one-step method for continuous large-scale synthesis of well-defined hollow titania spheres was established by feeding titanium tetrachloride mixed with ethanol vapor to a facile diffusion flame. A mixture of TiCl4 and C2H5OH vapor was transported at 100 m/s into a flame reactor and condensed into mesoscale droplets due to Joule–Thomson cooling and the entrainment of cool gases into the expanding high-speed jet. Hollow crystalline TiO2 spheres with good thermal stability were formed after the hydrolysis of TiCl4 in the H2/air flame at about 1500 °C. Structural characterization indicates that the hollow spheres, with uniform diameter of 300 nm and shell thickness of 35 nm, consist of 20–30 nm TiO2 nanocrystallites. A formation mechanism of the hollow spheres was proposed, involving the competition between chemical reaction and diffusion during the flame process. The present study provides a new pathway for continuous and large-scale engineering of hollow nanomaterials.Hollow crystalline TiO2 spheres with good thermal stability were prepared by the hydrolysis of TiCl4 in the H2/air flame at about 1500 °C. The hollow spheres, with uniform diameter of 300 nm and shell thickness of 35 nm, consist of 20–30 nm TiO2 nanocrystallites. The present study provides a new pathway for continuous and large-scale engineering of hollow nanomaterials.
Co-reporter:Dr. Hai Bo Jiang;Qian Cuan;Ci Zhang Wen;Jun Xing;Di Wu;Dr. Xue-Qing Gong;Dr. Chunzhong Li;Dr. Hua Gui Yang
Angewandte Chemie 2011 Volume 123( Issue 16) pp:3848-3852
Publication Date(Web):
DOI:10.1002/ange.201007771
Co-reporter:Dr. Hai Bo Jiang;Qian Cuan;Ci Zhang Wen;Jun Xing;Di Wu;Dr. Xue-Qing Gong;Dr. Chunzhong Li;Dr. Hua Gui Yang
Angewandte Chemie International Edition 2011 Volume 50( Issue 16) pp:3764-3768
Publication Date(Web):
DOI:10.1002/anie.201007771
Co-reporter:Qilin Cheng;Vladimir Pavlinek;Ying He;Yanfang Yan
Colloid and Polymer Science 2011 Volume 289( Issue 7) pp:799-805
Publication Date(Web):2011 May
DOI:10.1007/s00396-011-2398-8
TiO2 hollow microspheres with sea urchin-like hierarchical architectures were synthesized by a simple hydrothermal method. The as-synthesized hollow microspheres with hierarchical architectures consisting of many rhombic building units exhibit high specific surface area. Electrorheological (ER) properties of hierarchical hollow TiO2-based suspension were investigated under steady and oscillatory shear. The hollow TiO2-based suspensions show much higher yield stress and elasticity than pure TiO2 suspension at the same electric field strength. This phenomenon was elucidated well in view of their dielectric spectra analysis. The sea urchin-like architectures result in stronger interfacial polarization of hollow TiO2 suspension upon an electric field, showing higher ER activity. Also, hollow interiors of TiO2 particles increase the long-term stability of suspensions and further merit the ER effect.
Co-reporter:Yanjie Hu, Hongqiu Ding, Chunzhong Li
Particuology 2011 Volume 9(Issue 5) pp:528-532
Publication Date(Web):October 2011
DOI:10.1016/j.partic.2011.06.003
Hollow Al2O3 nanospheres with well-defined structure and shape were successfully prepared via flame spray pyrolysis (FSP) in the presence of a surfactant as droplet stabilizer. The morphology and structure of the nanospheres were systematically characterized by transmission electron microscopy, scanning electron microscopy, and N2 sorption. A solution of hydrated aluminum nitrate, polyethylene glycol (PEG) and absolute ethanol was sprayed into a flame to transform droplets into particles after evaporation and surface nucleation, forming hollow Al2O3 nanospheres from aluminum nitrate decomposition. The surfactant was found effective in producing smaller droplets because of decreased surface tension and viscosity, while the combination of oxygen atoms on PEG chains and aluminum ions in solution reduced interfacial turbulence, leading to increased stability of the droplets.The surfactant PEG was found effective in producing smaller droplets because of decreased surface tension and viscosity, while the combination of oxygen atoms on PEG chains and aluminum ions in solution reduced interfacial turbulence, leading to increased stability of the droplets.
Co-reporter:Wei Shao ; Feng Gu ; Chunzhong Li ;Mengkai Lu
Inorganic Chemistry 2010 Volume 49(Issue 12) pp:5453-5459
Publication Date(Web):May 27, 2010
DOI:10.1021/ic902553f
Uniform mesoporous TiO2 nanospheres were successfully developed via an interfacial confined formation process for application in dye-sensitized solar cells. The mesoporous spherical structures greatly promote the dye-loading capacity, electron transfer, and light scattering, resulting in remarkable enhancement of the cell performance. The designed interfacial platform caused a reaction-limited aggregation of the TiO2 nanocrystals, resulting in the formation of mesoporous spherical nanostructures with sphere diameter of 216 nm and pore size of 8 nm. The oriented attachment of adjacent TiO2 nanocrystals facilitated the electron transfer process when the mesoporous TiO2 nanospheres were used as electrode films. The dye coverage was enhanced remarkably in the mesoporous spherical TiO2 samples. Owing to the enhanced light-harvesting efficiency, solar conversion efficiency was enhanced about 30% for the dye-sensitized solar cell (DSSC) based on mesoporous spherical TiO2 in comparison with that made by commercial TiO2 nanoparticles.
Co-reporter:Haigang Kang, Yihua Zhu, Xiaoling Yang, Yujia Jing, Anezka Lengalova, Chungzhong Li
Journal of Colloid and Interface Science 2010 Volume 341(Issue 2) pp:303-310
Publication Date(Web):15 January 2010
DOI:10.1016/j.jcis.2009.09.050
Mesoporous silica nanofibers and Ag-doped composite nanoribbons were synthesized by a facile combination of an electrospinning technique and the sol–gel method. Tetraethyl orthosilicate, polyvinylpyrrolidone (PVP), triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), copolymer Pluronic P123, and silver nitrate (AgNO3) were the components of sol for the production of Ag-doped hybrid silica ribbons. Heat removal of structure-directing agent P123 in the hybrid fibers at high temperatures resulted in a mesoporous morphology, and the degradation of PVP caused AgNO3 to convert into silver in the form of nanoparticles. The size and content of the particles in the hybrid ribbons could be controlled by the concentration of AgNO3 and thermal treatment conditions. Scanning electron microscopy, N2 adsorption–desorption isotherm, transmission electron microscopy, X-ray diffraction, and UV–Vis spectroscopy were used to characterize the composite ribbons. The catalytic activity of the ribbons was evaluated by reduction of methylene blue dye and found to be better than in previous studies.The silver-doped mesoporous silica nanobibbons had been synthesized by combining the electrospinning technique and sol–gel method, which demonstrated high catalytic efficiency for reduction reaction of methylene blue dye (MB).
Co-reporter:Wei Shao, Feng Gu, Chunzhong Li, and Mengkai Lu
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 19) pp:9111-9116
Publication Date(Web):September 3, 2010
DOI:10.1021/ie901692z
The growth and assembly of TiO2 nanostructures with enhanced charge transfer and light harvesting have attracted much attention for fabricating highly efficient dye-sensitized solar cells. In this study, we report an environmentally friendly and easy synthetic route for fabrication of mesostructured anatase TiO2 by controlling the hydrolyzing of n-butyl titanate in boric acid solution. The well-defined mesoporous TiO2 aggregates are obtained by the tensorial reaction-limited aggregation probability. The photovoltaic measurements indicate that the mesoporous TiO2 layer enhances the dye loading capacity, the electron transfer efficiency, and the photocurrent of the cell, contributing to the significant improvement of the energy conversion efficiency of the dye-sensitized solar cells.
Co-reporter:Huiting Wang, Yanjie Hu, Ling Zhang and Chunzhong Li
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 8) pp:3654-3662
Publication Date(Web):March 23, 2010
DOI:10.1021/ie901782w
Self-cleaning transparent nanoporous films with high photocatalytic properties were obtained based on the self-assembly of TiO2 nanoparticles synthesized by H2/O2 combustion flames. Films were prepared from multilayer deposition of poly(sodium 4-styrenesulfonate)-treated TiO2 nanoparticles and SiO2 nanoparticles with electrostatic interaction by the adsorption of positively charged poly(diallyldimethylammonium chloride) via layer-by-layer assembly processes. The assembly conditions, such as the pH and concentration of a nanoparticle suspension that cause variation of the surface charge densities, were found to strongly affect the thickness and morphology of multilayer films. TiO2/SiO2 coatings assembled with 10 cycles reach effective photocatalysis with a maximum transmittance of 99.3% as well as a water droplet spreading time as short as 0.29 s. The photodegradation kinetics showed that multilayer films fabricated with 10 cycles are 4 times more active than films assembled with 5 cycles, indicating that flame-synthesized TiO2 with well crystallinity can be used to fabricate high transparent self-cleaning films at suitable assembly conditions. The photocatalytic degradation kinetics dominated by control of the number of assembled cycles was also discussed.
Co-reporter:Jie Liu, Feng Gu, Yanjie Hu and Chunzhong Li
The Journal of Physical Chemistry C 2010 Volume 114(Issue 13) pp:5867-5870
Publication Date(Web):March 11, 2010
DOI:10.1021/jp911628r
Well-crystalline SnO2 nanorods were first synthesized via a continuous and scalable iron-assisted flame approach with production rate up to 50 g/h in laboratory-scale. The as-prepared SnO2 nanorods with uniform length up to 200 nm and diameter around 20 nm are smooth and single crystal rutile structures, growing along the [001] direction. Iron dopant is incorporated into the SnO2 lattice and selectively effects a specific SnO2 crystal plane, promoting the further crystal oriented growth into nanorods. Meanwhile, the photoluminescence (PL) spectrum of such SnO2 nanorods exhibits a broad, stronger orange-emission peak around 620 nm, suggesting potential applications in optoelectronics. It is noteworthy that this dopant-assisted flame approach provides a new strategy for sequentially engineering one-dimensional nanomaterials.
Co-reporter:Chunzhong Li
Frontiers of Chemical Science and Engineering 2010 Volume 4( Issue 1) pp:18-25
Publication Date(Web):2010 March
DOI:10.1007/s11705-009-0305-3
Nanotechnology is already having a significant commercial impact, and will very certainly have a much greater impact in the future. The research on process engineering and scale-up will be very important for the commercial production and application of nanomaterials, because the properties and structure of nanomaterials are not only determined by the nucleation and growth process, but also strongly affected by the engineering properties, such as the mixing, the heat and mass transfer, and also the distribution of temperature, concentration, etc. This paper will present some research work in our laboratory on the fabrication of nanomaterials. Based on the chemical engineering principle and methods, many kinds of novel nanomaterials can be synthesized and their structure can be easily controlled through adjusting the parameters of the fluid mixing, and the distribution of temperature, residence time and concentration, etc. By using the micro-mixing, heat and mass transfer and reaction control methods, the host-guest nanocomposites have been assembled and assumed as the novel electroanalytical sensing nanobiocomposite materials. Based on the principles of chemical engineering, the manufacturing technologies for magnetic powders, calcium carbonate, and titanium dioxide have been developed for commercial-scale production, and the largest production scale has reached 15 kt/year.
Co-reporter:Haigang Kang, Yihua Zhu, Jianhua Shen, Xiaoling Yang, Cheng Chen, Huimin Cao, Chungzhong Li
Materials Research Bulletin 2010 45(7) pp: 830-837
Publication Date(Web):
DOI:10.1016/j.materresbull.2010.03.010
Co-reporter:Haigang Kang, Yihua Zhu, Yujia Jing, Xiaoling Yang, Chungzhong Li
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2010 Volume 356(1–3) pp:120-125
Publication Date(Web):5 March 2010
DOI:10.1016/j.colsurfa.2010.01.009
Mesoporous Ag-doped silica nanostructured ribbons were first synthesized by a facile combination of electrospinning technique and sol–gel method. Tetraethyl orthosilicate, polyvinylpyrrolidone (PVP), triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) copolymer Pluronic P123 and silver nitrate (AgNO3) were the components of sol for the production of Ag-doped hybrid silica ribbons. Heat removal of structure-directing agent P123 in the hybrid fibers at high temperatures resulted in mesoporous morphology, and the degradation of PVP made AgNO3 convert into silver in the form of nanoparticles. SEM, TEM, XRD, and UV–vis spectroscopy were used to characterize the ribbons. The ribbons with high width/height ratio have uniform and continuous morphology. Faradaic-impedance spectra and cyclic voltammetry test show that the ribbons have excellent ability of electron transition and electrochemical activity, expected to have potential application in biosensing system.
Co-reporter:Zhen Zhang, Yihua Zhu, Xiaoling Yang, Chunzhong Li
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2010 Volume 362(1–3) pp:135-139
Publication Date(Web):5 June 2010
DOI:10.1016/j.colsurfa.2010.04.006
A novel preparation method of azithromycin (AZI) microcapsules based on hollow polyelectrolyte (PE) microcapsules, which were prepared by layer-by-layer self-assembly onto the surface of silica microsphere (SiO2) followed by core dissolution has been investigated. The prepared AZI/PE microcapsules with an average diameter 1.2 μm possess homogeneous size and regular spherical shape. FTIR spectra and XRD patterns indicated that AZI molecular structure was not changed and AZI crystal state changed from monohydrate to dihydrate. The drug release experimental results showed an obvious improvement in the dissolution rate of the prepared AZI/PE microcapsules in comparing with AZI raw material drug powder.
Co-reporter:Chunzhong Li, Yanjie Hu, Weikang Yuan
Particuology 2010 Volume 8(Issue 6) pp:556-562
Publication Date(Web):December 2010
DOI:10.1016/j.partic.2010.08.009
The flame technology has been employed broadly for large-scale manufacture of carbon blacks, fumed silica, pigmentary titania, and also ceramic commodities such as SiO2, TiO2, and Al2O3. A deeper understanding of the process also made it possible for production of novel nanomaterials with high functionality—various novel nanomaterials such as nanorods, nanowires, nanotubes, nanocoils, and nanocomposites with core/shell, hollow and ball-in-shell structures, have been synthesized recently via gas combustion technology, while the mechanisms of the material formation were investigated based on the nucleation-growth and chemical engineering principles. Studies of the fluid flow and mass mixing, supported by principles of chemical reaction engineering, could provide knowledge for better understanding of the process, and thus make rational manipulation of the products possible.Various nanomaterials such as nanorods, nanowires, nanotubes, nanocoils, and nanocomposites with core/shell, hollow and ball-in-shell structures, have been synthesized recently via gas combustion technology, while the mechanisms of the material formation were investigated based on the nucleation-growth and chemical engineering principles.
Co-reporter:Zheming Gu;Chunzhong Li;Gengchao Wang;Ling Zhang;Xiaohui Li;Wendong Wang;Shilei Jin
Journal of Polymer Science Part B: Polymer Physics 2010 Volume 48( Issue 12) pp:1329-1335
Publication Date(Web):
DOI:10.1002/polb.22031
Abstract
This work demonstrates a feasible route to synthesize the layered polypyrrole/graphite oxide (PPy/GO) composite by in situ emulsion polymerization in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) as emulsifier. AFM and XRD results reveal that the GO can be delaminated into nanosheets and well dispersed in aqueous solution in the presence of CTAB. The PPy nanowires are formed due to the presence of the lamellar mesostructured (CTA)2S2O8 as a template. The results of the PPy/GO composite indicate the PPy insert successfully into GO interlayers, and the nanofiber-like PPy are deposited onto the GO surface. Owing to π–π electron stacking effect between the pyrrole ring of PPy and the unoxided domain of GO sheets, the electrical conductivity of PPy/GO composite (5 S/cm) significantly improves in comparison with pure PPy nanowires (0.94 S/cm) and pristine GO (1 × 10−6 S/cm). © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1329–1335, 2010
Co-reporter:Junqing He;Ling Zhang ;Chunzhong Li
Polymer Engineering & Science 2010 Volume 50( Issue 11) pp:2153-2159
Publication Date(Web):
DOI:10.1002/pen.21750
Abstract
The polyoxymethylene (POM) composites with different copper contents were prepared by extrusion. The thermal conductivity and tribological behavior of POM-Cu composites with various contents of copper particles were investigated by a hot disk thermal analyzer and an M-2000 friction and abrasion testing machine, respectively. The effect of copper particles on the thermal conductivity of POM composites was negligible when copper content was below 10 wt %. As the copper content increased, the thermal conductivity of composites increased and reached 0.477 W m−1 K−1 for POM-25 wt % Cu composite, which increased by 35.9% compared with that of unfilled POM. The incorporation of copper particles into POM reduced the friction coefficient of POM composites. The wear mechanisms of POM-Cu composites were adhesive and abrasive wear. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Co-reporter:Hao Jiang, Junqing Hu, Feng Gu, Wei Shao and Chunzhong Li
Chemical Communications 2009 (Issue 24) pp:3618-3620
Publication Date(Web):12 May 2009
DOI:10.1039/B904408F
Novel In2O3 hollow microspheres were successfully prepared by a hydrothermal then annealing process; the microspheres exhibited a quick response to dilute ethanol and quick recovery.
Co-reporter:Yihua Zhu, Huimin Cao, Longhua Tang, Xiaoling Yang, Chunzhong Li
Electrochimica Acta 2009 Volume 54(Issue 10) pp:2823-2827
Publication Date(Web):1 April 2009
DOI:10.1016/j.electacta.2008.11.025
Three-dimensional macroporous TiO2 was synthesized by a sol–gel procedure using polystyrene colloidal crystals as templates. SEM showed that a face-centered cubic (FCC) 3D macroporous structure was obtained. Horseradish peroxidase (HRP) was successfully immobilized on the surface of an optically transparent electrode (OTE). Photoelectrochemical properties were characterized using a three electrodes system and an ultraviolet lamp. The HRP/TiO2/OTE displays a rapid photocurrent response, approximately 178.7 nA, under UV illumination (380 nm). The sensitivity of H2O2 detection was 70.04 μA/mM without UV illumination, and it increased to 102.97 μA/mM when illuminated by UV. The amperometric response was also enhanced. The high response was due to the good biocompatibility of TiO2 and excellent photoelectrical property and the large effective surface of the three-dimensionally ordered macroporous structure.
Co-reporter:Hongkang Wang, Wei Shao, Feng Gu, Ling Zhang, Mengkai Lu and Chunzhong Li
Inorganic Chemistry 2009 Volume 48(Issue 20) pp:9732-9736
Publication Date(Web):September 18, 2009
DOI:10.1021/ic901235n
Anatase TiO2 nanoshuttles have been successfully prepared via a hydrothermal method under alkaline conditions by employing titanate nanowires as the self-sacrificing precursors. The experimental results showed that a radical structural rearrangement took place from titanate wires to anatase TiO2 shuttles during the hydrothermal reaction on the basis of a dissolution−recrystallization process. The surface of titanate nanowires plays a key role in the transformation process by providing both the structural units (e.g., TiO6 octahedra) to realize anatase transformation and locations for the deposition and rearrangement of the dissolved structural units, while the formation of shuttle morphology is attributed to the minimization of surface energy with thermodynamically stable (101) facets of anatase TiO2. The shape and phase transformation process were foundto be dependent on the hydrothermal reaction time. Raman and photoluminescence spectra confirmed the crystalline nature of the TiO2 nanoshuttles.
Co-reporter:Lanjuan Wang, Chunzhong Li, Feng Gu, Chuanxiang Zhang
Journal of Alloys and Compounds 2009 Volume 473(1–2) pp:351-355
Publication Date(Web):3 April 2009
DOI:10.1016/j.jallcom.2008.05.095
Carbon nanocoils (CNCs) were in situ synthesized by using tin oxide nanoparticle catalyst from stannic chloride precursor in an ethanol flame. The anisotropic deposition rate of carbon among tin dioxide crystal planes provides the driving force for the coiling of carbon fibers. The obtained CNCs have tight coil pitches and average fiber and coil diameter of approximately 50–80 nm and 80–100 nm, respectively. BET measurement and BJH method reveal that the CNCs possess a mesoporous character. The CNCs present excellent specific capacitance as ca. 40 F/g using as polarized electrodes, which is considerably higher than that of the micro-coiled carbon fibers or carbon nanofibers, maybe the ideal candidate using as supercapacitor.
Co-reporter:Jie Liu, Yanjie Hu, Feng Gu and Chunzhong Li
Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 2) pp:735-739
Publication Date(Web):December 9, 2008
DOI:10.1021/ie800986j
Ball-in-shell structured TiO2 nanospheres were successfully made by flame synthesis—a single-step, continuous, and scalable process. The morphology and structure were systematically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and N2 sorption. TiO2 nanostructures with good crystalline nature and thermal stability were formed by feeding a titanium tetrachloride and alcohol vapor mixture to a facile diffusion flame. The resultant ball-in-shell spheres were composed of nanocrystallites, with shell thickness and void space width of 30−50 nm and 10−30 nm, respectively. The formation mechanism of ball-in-shell spheres was investigated, depending on the competition between the chemical reaction rate and diffusion rate during the flame process. Furthermore, UV−vis characterization indicates that this structure endows the spheres with higher light absorbance, which may be favorable to design and prepare novel materials with enhanced photocatalytic activities.
Co-reporter:Yaoxia Li, Yihua Zhu, Cuiyan Li, Xiaoling Yang, Chunzhong Li
Materials Letters 2009 Volume 63(Issue 12) pp:1068-1070
Publication Date(Web):15 May 2009
DOI:10.1016/j.matlet.2009.02.007
The ZnS nanoparticles were exclusively synthesized in the pores of the mesoporous silica (MS) particles which had been coated with two bilayers of poly(allylamine hydrochloride) (PAH)/poly(styrene sulfonate) (PSS) via the layer-by-layer (LbL) self-assembly technique. Measurements and analysis of XRD and TEM showed that the ZnS nanocrystals were inserted into the pores of the MS spheres. This approach can be used to prepare composite materials involving functional inorganic nanoparticles which have potential application in biological immunoassay and photoelectronic fields.
Co-reporter:Junqing He;Wei Shao;Ling Zhang;Chao Deng ;Chunzhong Li
Journal of Applied Polymer Science 2009 Volume 114( Issue 2) pp:1303-1311
Publication Date(Web):
DOI:10.1002/app.30614
Abstract
The aim of this study was to investigate the crystallization behavior and UV-protection property of polyethylene terephthalate (PET)-ZnO nanocomposits. PET-ZnO nanocomposites containing 0.5–3.0 wt % of ZnO were successfully synthesized by in situ polymerization. The Fourier transformed infrared (FTIR) spectroscopy indicated the silane coupling agent was anchored onto the surface of ZnO. Scanning electron microscope (SEM) images showed ZnO particles were dispersed homogeneously in PET matrix with amount of 0.5–1.0 wt %. Differential scanning calorimetry (DSC) results exhibited that the incorporation of ZnO into PET resulted in increase of the melting transition temperature (Tm) and crystallization temperature (Tc) of PET-ZnO nanocomposites. The crystallization behavior of PET and PET-ZnO nanocomposites was strongly affected by cooling rate. ZnO nanoparticles can act as an efficient nucleating agent to facilitate PET crystallization. UV–vis spectrophotometry showed that UV-ray transmittance of PET-ZnO nanocomposites decreased remarkably and reached the minimum value of 14.3% with 1.5 wt % of ZnO, compared with pure PET whose UV-ray transmittance was 84.5%. PET-ZnO nanocomposites exhibited better UV-protection property than pure PET, especially in the range of UVA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Qilin Cheng;Vladimir Pavlinek;Ying He;Chunzhong Li
Colloid and Polymer Science 2009 Volume 287( Issue 4) pp:435-441
Publication Date(Web):2009 April
DOI:10.1007/s00396-008-1985-9
In this paper, one-dimensional polyaniline/titanate (PANI/TN) composite nanotubes were synthesized by in situ chemical oxidative polymerization directed by block copolymer. These novel nanocomposite particles were used as a dispersed phase in electrorheological (ER) fluids, and the ER properties were investigated under both steady and dynamic shear. It was found that the ER activity of PANI/TN fluids varied with the ratio of aniline to titanate, and the PANI/TN suspensions showed a higher ER effect than that made by sphere-like PANI/TiO2 nanoparticles. These observations were well interpreted by their dielectric spectra analysis; a larger dielectric loss enhancement and a faster rate of interfacial polarization were responsible for a higher ER activity of nanotubular PANI/TN-based fluids.
Co-reporter:Hao Jiang, Junqing Hu, Feng Gu, Chunzhong Li
Particuology 2009 Volume 7(Issue 3) pp:225-228
Publication Date(Web):June 2009
DOI:10.1016/j.partic.2009.01.010
Wurtzite ZnO microspheres, 5.5–11 μm in diameter and with smooth surfaces, were prepared in absolute ethanol via a simple template-free method in the presence of ethylenediamine. The products were characterized using X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. This simple method to fabricate ZnO microspheres shows high yield (>90%) and good reproducibility. The formation process of ZnO microspheres was discussed. The as-obtained ZnO microspheres are expected to provide some immediate advantages for optical, microelectronic, and biological applications.
Co-reporter:Jinjie Sun, Yihua Zhu, Xiaoling Yang, Chunzhong Li
Particuology 2009 Volume 7(Issue 5) pp:347-352
Publication Date(Web):October 2009
DOI:10.1016/j.partic.2009.04.009
A novel photoelectrochemical biosensor incorporating nanosized CdS semiconductor crystals with enzyme to enhance photochemical reaction has been investigated. CdS nanoparticles were synthesized by using dendrimer PAMAM as inner templates. The CdS nanoparticles and glucose oxidase (GOD) were immobilized on Pt electrode via layer-by-layer (LbL) technique to fabricate a biological–inorganic hybrid system. Under ultraviolet light, the photo-effect of the CdS nanoparticles showed enhancement of the biosensor to detect glucose. Pt nanoparticles were mixed into the Nafion film to immobilize the CdS/enzyme composites and to improve the charge transfer of the hybrid. Experimental results demonstrate the desirable characteristics of this biosensing system, e.g. a sensitivity of 1.83 μA/(mM cm2), lower detection limit (1 μM), and acceptable reproducibility and stability.
Co-reporter:Jitao Chen, Feng Gu and Chunzhong Li
Crystal Growth & Design 2008 Volume 8(Issue 9) pp:3175-3179
Publication Date(Web):July 23, 2008
DOI:10.1021/cg700719h
An improved process for the preparation of SrAl2O4:Eu,Dy phosphors was developed by introducing a precalcination process for the precursor synthesized via the coprecipitation method. The structural and initial photoluminescent characteristics of these SrAl2O4:Eu,Dy phosphors were investigated using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), electron paramagnetic resonance (EPR), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence spectroscopy (PL). The experimental results revealed that the precalcination process could facilitate the doped boron’s effect as a flux along with the formation of more oxygen vacancies around Eu2+ ions, which resulted in the remarkable increase of the initial photoluminescent intensity of the samples. When the doping concentration of boron was 30%, the obtained SrAl2O4:Eu,Dy sample possessed a photoluminescent intensity two times higher than that of the sample prepared without the precalcination process. The boron doping also induced the appearance of Sr4Al14O25 phase in the sample and an obvious blue shift of the emission band can be observed. Due to the promising initial photoluminescent properties, the as-prepared SrAl2O4:Eu,Dy samples show potential display applications in particular areas.
Co-reporter:Shufen Wang, Hongming Cao, Feng Gu, Chunzhong Li, Guangjian Huang
Journal of Alloys and Compounds 2008 Volume 457(1–2) pp:560-564
Publication Date(Web):12 June 2008
DOI:10.1016/j.jallcom.2007.03.079
Magnetic iron/silica core/shell nanostructures were prepared by reducing the initially formed α-Fe2O3/SiO2 composites prepared via a sonication-assisted Stöber process. Monodisperse α-Fe2O3 nanocrystals were prepared by a simple solution method using PEG as a surfactant. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, (high-resolution) transmission electron microscopy ((HR)TEM), scanning electron microscopy (SEM) and magnetic hysteresis loops. After the reduction process, the silica coating can protect the Fe core from oxidation effectively. And the formed Fe/SiO2 nanostructures show better magnetic behavior, which is promising in targeted drug delivery systems.
Co-reporter:Qiuling Zhou, Chunzhong Li, Feng Gu, H.L. Du
Journal of Alloys and Compounds 2008 Volume 463(1–2) pp:317-322
Publication Date(Web):8 September 2008
DOI:10.1016/j.jallcom.2007.09.021
Multi-walled carbon nanotubes grew directly on wires of stainless steel mesh in controllable methane diffusion flames. The formation and morphology of carbon nanotubes were dependent on gas composition of the flames. On pre-etched mesh wires with HCl, high density of carbon nanotubes were synthesized with uniform outer diameters of 60 nm and large inner diameters of 50 nm. With the high yield of carbon nanotubes, less carbon impurities were formed in the process. A mechanistic model was proposed in detail to suggest the formation of catalyst directly on bulk surface and explain the whole process of carbon nanotubes growth in this study.
Co-reporter:Hongming Cao;Jun Gan;Shufen Wang;Shaofeng Xuan;Qiufang Wu;Chunzhong Li;Chuntao Wu;Chengen Hu;Guangjian Huang
Journal of Biomedical Materials Research Part A 2008 Volume 86A( Issue 3) pp:671-677
Publication Date(Web):
DOI:10.1002/jbm.a.31647
Abstract
Novel silica-coated iron–carbon composite particles were prepared to be used in the targeting therapy as a drug carrier. The composite particles with diameter of 200–300 nm were obtained successfully via high-energy planetary ball milling and hydrogen reduction processes. The composite particles possess the advantages of activated carbon and magnetic Fe, exhibiting excellent drug adsorption and desorption abilities as well as powerfully magnetic targeting. In in vivo experiment, 99mTcO4-adsorbed composite particles showed prominent biodistribution in the left hepatic lobe of pigs under the control of an external magnetic field. The amount of doxorubicin content of hepatic tissue was 23.8 times higher in targeted area of the left lobe than that in the nontargeted area of the right lobe when doxorubicin-adsorbed composite particles were infused intra-arterially. These results also suggest that the composite particles could penetrate through the capillary wall around tissue interstitium and hepatic cells under the driving of an external magnetic force in targeting area, indicating that the novel silica-coated iron–carbon composite particles could be a potential application in targeted treatment for some kinds of tumor as an effective drug carrier. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Co-reporter:Hongming Cao, Guangjian Huang, Shaofeng Xuan, Qiufang Wu, Feng Gu, Chunzhong Li
Journal of Alloys and Compounds 2008 Volume 448(1–2) pp:272-276
Publication Date(Web):10 January 2008
DOI:10.1016/j.jallcom.2006.10.019
Special carbon-coated iron core/shell nanoparticles have been synthesized via a simple chemical vapor deposition (CVD) process. The experimental results show the iron nanoparticles are really encapsulated within an inhomogeneous carbon layer. The formation of amorphous carbon layer as well as the magnetic Fe nanoparticles makes this core/shell structure exhibit good drug adsorption and release capability, suggesting potential applications in targeted drug delivery systems.
Co-reporter:Yin Zhao, Chunzhong Li, Xiuhong Liu, Feng Gu, H.L. Du, Liyi Shi
Materials Chemistry and Physics 2008 Volume 107(2–3) pp:344-349
Publication Date(Web):15 February 2008
DOI:10.1016/j.matchemphys.2007.07.026
Via properly changing concentration of titanium precursor, tuning the residence time and controlling of the temperature field in the reaction region, nanocrystalline TiO2 powders were synthesized by the diffusion flame method with well-dispersed behavior and controlled crystal structures and particles size. The XPS and IR results showed that there existed high hydration and oxygen vacancies on the surface of the as-prepared nanocrystalline TiO2 powders, which played a dominant role in controlling polymorph fraction by altering the critical particles size of phase transition. The thermodynamics analysis demonstrated that the high hydration on TiO2 surface can produce the lattice contraction, which effectively stabilizes anatase phase. However, the oxygen vacancies on TiO2 surface can decrease activation energy of phase transition of anatase to rutile, which facilitates the phase transformation.
Co-reporter:Qilin Cheng, Ying He, Vladimir Pavlinek, Chunzhong Li, Petr Saha
Synthetic Metals 2008 Volume 158(21–24) pp:953-957
Publication Date(Web):December 2008
DOI:10.1016/j.synthmet.2008.06.022
In this work, we demonstrate a simple route to the preparation of bulk quantities of polypyrrole/titanate (PPy/TN) composite nanofibers using cetyl trimethylammonium bromide (CTAB) as a structure-directing agent. Titanate (TN) nanowires and CTAB act as a template for fabrication of the composite nanofibers. The structural characterization shows that the resulting nanocomposite exhibits core-shell nanofiber networks and the average diameter of the nanofibers is around 50–90 nm. The electrical conductivity measurements reveal that the addition of TN nanowires slightly enhances the conductivity of the composite. The ac conductivity follows the power law, which varies with the mass ratio of pyrrole monomer to TN. A possible mechanism is also proposed to interpret the formation of the PPy/TN composite nanofiber networks.
Co-reporter:Xiaolei Chen;Chunzhong Li;Wei Shao;Tianxi Liu;Lumin Wang
Journal of Applied Polymer Science 2008 Volume 109( Issue 6) pp:3753-3762
Publication Date(Web):
DOI:10.1002/app.28069
Abstract
Poly(ethylene terephthalate) (PET)/antimony-doped tin oxide (ATO) nanocomposites were prepared by in situ polymerization. The nonisothermal crystallization behaviors of neat PET and PET/ATO nanocomposites were investigated with differential scanning calorimetry. The nonisothermal crystallization data were analyzed with the Avrami analysis modified by Jeziorny, the Ozawa method, and a method developed by Liu et al. The modified Avrami equation could describe only the primary stage of nonisothermal crystallization of PET and PET/ATO nanocomposites. The Ozawa analysis, when applied to the polymer systems studied here, failed to describe their nonisothermal crystallization behavior. The kinetic method developed by Liu et al. was successful in describing the nonisothermal crystallization of neat PET and PET/ATO nanocomposites. According to the Kissinger equation, the activation energies were determined to be −205.3, −220.0, and −243.7 kJ/mol for neat PET and 99/1 and 95/5 PET/ATO nanocomposites, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Co-reporter:Qilin Cheng, Vladimir Pavlinek, Ying He, Anezka Lengalova, Chunzhong Li, Petr Saha
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2008 Volume 318(1–3) pp:169-174
Publication Date(Web):1 April 2008
DOI:10.1016/j.colsurfa.2007.12.044
In this work, mesoporous silica (MCM-41) was modified by triethanolamine (TEA) by a wet impregnation method. The structure and morphology of modified MCM-41 particles were characterized by X-ray diffraction, N2 adsorption/desorption, Fourier-transform infrared spectra, scanning electron microscopy, particle size analyzer and thermogravimetric analysis. The results show that the interior channels of MCM-41 are modified by TEA without destroying its mesoporous structure. Further, pure MCM-41and TEA-modified particles were adopted as dispersed phase in silicone oil for electrorheological (ER) investigation. The TEA-MCM-41 (modified with 7 wt.% TEA)-based ER fluid with a volume fraction of 5% exhibits stronger ER activity than pure MCM-41 fluid. The possible mechanism related to dielectric properties is also provided.
Co-reporter:Fei Wang, Gengchao Wang, Shu Yang and Chunzhong Li
Langmuir 2008 Volume 24(Issue 11) pp:5825-5831
Publication Date(Web):April 30, 2008
DOI:10.1021/la8000625
Poly(aniline-co-o-anisidine) (P(An-co-o-As)) ionomers and poly(sodium 4-styrenesulfonate) (PSS) were layer-by-layer (LbL) assembled on carboxylic acid-functionalized multiwalled carbon nanotubes (MWNTs). The multilayered polyelectrolyte greatly enhanced the dispersibility and stability of MWNTs in aqueous solutions. More importantly, the nanocomposites showed 3 orders of magnitude of conductivity increase, 4.2 S/cm, compared to that of neat ionomers, 0.004 S/cm. The deposition procedure was monitored with zeta (ζ) potential changes. Fourier transform infrared (FT-IR), ultraviolet−visible (UV–vis), and Raman spectra confirmed charge transfer from the quinoid units of the P(An-co-o-As) to MWNTs, which effectively delocalize the electrons. Further, we explored the pH response of the assembled P(An-co-o-As)/PSS/MWNTs multilayer nanocomposites. The sharp transition of the conductivity in the pH range of 2 to 6 makes the nanocomposites promising candidates for chemical-biological sensing.
Co-reporter:Hao Jiang ; Junqing Hu ; Feng Gu ;Chunzhong Li
The Journal of Physical Chemistry C 2008 Volume 112(Issue 32) pp:12138-12141
Publication Date(Web):July 17, 2008
DOI:10.1021/jp8024232
Large-scaled and monodispersed ZnO microspheres have been prepared successfully by using triethanolamine (TEA) aqueous solution as solvent at low reaction temperature ranging from 150 to 200 °C. The diameters of ZnO microspheres with narrow size distribution ranging (<8%) can be tuned from ∼670 to ∼1150 nm only by changing the reaction temperature, and each ZnO microsphere is composed of numerous ZnO aggregates nanocrystallines with diameters of 16.4−21.9 nm. A mechanism for the formation of ZnO microspheres has been proposed, in which TEA plays a crucial role in the formation of the wurtzite ZnO microspheres. Room-temperature photoluminescence spectra of the ZnO microspheres reveal a strong emission peak at 391 nm and several weak emission peaks at 420, 484, and 530 nm, respectively.
Co-reporter:Shufen Wang, Feng Gu, Chunzhong Li and Mengkai Lü
Crystal Growth & Design 2007 Volume 7(Issue 12) pp:2670
Publication Date(Web):November 8, 2007
DOI:10.1021/cg070111a
Mesoporous Eu2O3 microspindles have been prepared by a facile solution process followed by subsequent heat treatment. By adding urea stepwise and varying the reaction time, the dimension of the Eu2O3 microspindles can be easily tuned from 250 × 100 nm to 900 × 400 nm. The products were characterized by X-ray diffraction, small-angle X-ray scattering, (high-resolution) transmission electron microscopy, scanning electron microscopy, N2 adsorption, and photoluminescence spectroscopy. The Eu2O3 samples exhibit a relatively broad pore-size distribution, and the wall of the pore is constructed by well-crystalline Eu2O3 nanocrystals with diameters of about 15 nm. A possible formation mechanism of the mesoporous microspindles was also discussed.
Co-reporter:Qilin Cheng, Vladimir Pavlinek, Ying He, Chunzhong Li, Anezka Lengalova, Petr Saha
European Polymer Journal 2007 Volume 43(Issue 9) pp:3780-3786
Publication Date(Web):September 2007
DOI:10.1016/j.eurpolymj.2007.06.040
In this work, we present a facile method for preparation of novel polyaniline(PANI)/titanate composite nanotubes by in situ chemical oxidative polymerization directed by poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer. The block copolymer adsorbed onto the surface of the titanate nanotubes acts as a soft template. The obtained nanocomposite has a core–shell structure in which titanate nanotubes are encapsulated by uniform PANI layers. Their structure and morphology were characterized by various experimental techniques. A possible formation mechanism of composite nanotubes is also proposed in the paper.
Co-reporter:Xiaolei Chen;Chunzhong Li;Wei Shao;Junqing He
Journal of Applied Polymer Science 2007 Volume 105(Issue 5) pp:2783-2790
Publication Date(Web):15 MAY 2007
DOI:10.1002/app.26511
Antimony doped tin oxide (ATO) nanoparticles modified poly(ethylene terephthalate) (PET) composites used for manufacturing antistatic PET fiber were synthesized by in situ polymerization. The crystallization and multiple melting behavior of the nanocomposites were systemically investigated by means of Differential Scanning Calorimeter (DSC), Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD) techniques. The degree of crystallinity in nanocomposites increased with increasing ATO content. Smaller and more incomplete crystals are presented in the crystalline regions of the nanocomposites with increasing the content of ATO, which could be attributed to heterogeneous nucleation effects of ATO nanoparticles. Dynamic Mechanical Analysis (DMA) measurements showed that the storage moduli of the nanocomposites increased with increasing the content of ATO, due to formation of immobilized layer between polymer and filler. The interactions between ATO and PET molecules result in high tan δ for the PET/ATO nanocomposites. Percolation threshold of PET/ATO hybrid fibers prepared by the nanocomposites at room temperature was as low as 1.05 wt %, much lower than that of the composites filled with conventional conductive particles. Adding ATO nanoparticles obviously improves the conductivity of PET. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Co-reporter:Xiaolei Chen;Chunzhong Li;Wei Shao;H. L. Du;J. S. Burnell-Gray
Journal of Applied Polymer Science 2007 Volume 105(Issue 3) pp:1490-1495
Publication Date(Web):23 APR 2007
DOI:10.1002/app.26381
Poly(ethylene phthalate) (PET)/nano-antimony doped tin oxide (ATO) composites prepared via in situ polymerization were spun into fiber by the melt-spinning process. ATO were in the form of loose agglomeration dispersing in the PET fibers and the sizes of loose agglomeration were smaller than 150 nm. Comparing with the neat PET, the tenacity of PET/ATO hybrid fibers was improved, and PET/ATO hybrid fibers had a lower elongation at break by adding nano-ATO. The percolation threshold of PET/ATO hybrid fibers at room temperature was as low as 1.05 wt %, much lower than that of the composites filled with conventional conductive particles. The PET/ATO hybrid fiber exhibited volume resistivity of 4.9 × 108 Ω cm when the contents of ATO were 1 wt %. The ATO nanoparticles improved the thermal stability of PET fiber. The WAXD and DSC results suggested that ATO nanoparticles increase the degree of crystallinity of PET acting as the nucleating agent, which prohibited the thermal shrinkage of PET fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Co-reporter:Yin Zhao, Chunzhong Li, Xiuhong Liu, Feng Gu, Haibo Jiang, Wei Shao, Ling Zhang, Ying He
Materials Letters 2007 Volume 61(Issue 1) pp:79-83
Publication Date(Web):January 2007
DOI:10.1016/j.matlet.2006.04.010
Ultrafine TiO2 particles have been synthesized successfully by a facile gas flame combustion method. The synthesized sample is characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared (FTIR), and photoluminescence (PL) spectroscopy. The as-prepared TiO2 nanoparticles appear to be a single anatase crystalline phase and the diameter is about 9 nm. Besides a sharp emission at 398 nm originating from the radiative annihilation of excitions, a weak broad band at about 434 nm from the defect-related emission is also discussed.
Co-reporter:Qilin Cheng, Chunzhong Li, Vladimir Pavlinek, Petr Saha, Huanbing Wang
Applied Surface Science 2006 Volume 252(Issue 12) pp:4154-4160
Publication Date(Web):15 April 2006
DOI:10.1016/j.apsusc.2005.06.022
Abstract
Studies were performed on surface modification of antibacterial TiO2/Ag+ nanoparticles by grafting γ-aminopropyltriethoxysilane (APS). The interfacial structure of the modified particles was characterized by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis. The thickness of the surface layer was determined by using Auger electron spectroscopy (AES). The results show that APS is chemically bonded to the surface of antibacterial TiO2/Ag+ nanoparticles. Furthermore, the modified particles were mixed in PVC to prepare composites whose antibacterial property was investigated. The results suggest that surface modification has no negative effect on antibacterial activity of TiO2/Ag+ nanoparticles and PVC–TiO2/Ag+ composites exhibits good antibacterial property.
Co-reporter:Qilin Cheng, Vladimir Pavlinek, Anezka Lengalova, Chunzhong Li, Ying He, Petr Saha
Microporous and Mesoporous Materials 2006 Volume 93(1–3) pp:263-269
Publication Date(Web):28 July 2006
DOI:10.1016/j.micromeso.2006.03.005
A new nanocomposite with conducting polypyrrole (PPy) confined in ordered mesoporous silica SBA-15 channels has been synthesized by an in situ polymerization technique. The resulting material was characterized by X-ray diffraction (XRD), N2 adsorption/desorption, high-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectra (FT-IR) and thermogravimetric analysis (TGA). The results show that PPy is formed in the channels instead of coating the outer surface of SBA-15 and nanocomposite possesses well-ordered hexagonal structure. Further, nanocomposite particles were used as dispersed phase in silicone oil for electrorheological (ER) investigation. Suspension of PPy–SBA-15 displays notable ER characteristics under external electric fields.
Co-reporter:Shuisheng Sun, Chunzhong Li, Ling Zhang, H.L. Du, J.S. Burnell-Gray
European Polymer Journal 2006 Volume 42(Issue 7) pp:1643-1652
Publication Date(Web):July 2006
DOI:10.1016/j.eurpolymj.2006.01.012
Poly(vinyl chloride) (PVC)-based composites were prepared by blending PVC with nano-SiO2 particles, which were treated with dimethyl dichlorosilane (DMCS), γ-methylacryloxypropyl trimethoxy silane (KH570). The dispersion and interfacial compatibility of nano-SiO2 particles in PVC matrix was characterized by SEM, which indicated that DDS had a better dispersion and compatibility than UTS but worse than KHS. The mechanical properties, processability and effective interfacial interaction of nano-SiO2/PVC composites were studied. The nano-SiO2 particles treated with KH570 or DMCS significantly reinforced and toughened the PVC composites. The maximum impact strength of PVC composites was achieved at a weight ratio of nano-SiO2/PVC:4/100. The tensile yield stress increased with increasing the content of treated inorganic particles. The incorporation of untreated nano-SiO2 particles adversely affected the tensile strength of the composite. Although the equilibrium torques of all nano-SiO2/PVC composites were higher than that of pure PVC, the surface treatments did reduce the equilibrium torque. The interfacial interaction parameter, B, and interfacial immobility parameter, b, calculated respectively from tensile yield stress and loss module of nano-SiO2/PVC composites, were employed to quantitatively characterize the effective interfacial interaction between the nano-SiO2 particles and PVC matrix. It was demonstrated that the nano-SiO2 particles treated with KH570 had stronger effective interface interaction with PVC matrix than those treated with DMCS, which also had stronger effective interface interaction than the untreated nano-SiO2 particles.
Co-reporter:Qilin Cheng, Vladimir Pavlinek, Chunzhong Li, Anezka Lengalova, Ying He, Petr Saha
Materials Chemistry and Physics 2006 Volume 98(2–3) pp:504-508
Publication Date(Web):1 August 2006
DOI:10.1016/j.matchemphys.2005.09.074
A new nanocomposite, semiconducting polypyrrole (PPy) confined in mesoporous silica (MCM-41) has been synthesized. PPy was formed in the pores of MCM-41 by adsorption of pyrrole gas and subsequent oxidative polymerization with FeCl3·6H2O. Different techniques were used to characterize the nanocomposite formation. X-ray diffraction (XRD) and N2 adsorption/desorption analysis show that the nanocomposite possesses mesoporous structure, and the residual pore volume of nanocomposite is significantly lower than that of pure empty MCM-41. FTIR spectra, high resolution transmission electron micrographs and electrical conductivity measurements confirmed the presence of polypyrrole inside pore channels of the host, and thermogravimetric analysis proved confinement effect in the channel system.
Co-reporter:Chunzhong Li, Liyi Shi, Dongmei Xie, Hailiang Du
Journal of Non-Crystalline Solids 2006 Volume 352(38–39) pp:4128-4135
Publication Date(Web):15 October 2006
DOI:10.1016/j.jnoncrysol.2006.06.036
Al-doped titanium dioxide nanoparticles with precisely controlled characteristics were synthesized in an aerosol reactor between 900 °C and 1500 °C by vapor-phase oxidation of titanium tetrachloride. The effect of process variables (reactor temperature, initial TiCl4 concentration, residence time and feeding temperature of oxygen) on particle morphology and phase characteristics was investigated using TEM, XRD, EDS, ICP and XPS, etc. The average particle size increased with decreasing oxygen feeding temperature and increasing reaction temperature, residence time and TiCl4 concentration. The presence of aluminum during gas phase reaction increased the rate of phase transformation from anatase to rutile and altered the particle morphology from polyhedral to irregular crystals. TiO2 and Al2O3 co-precipitated during particle formation which lead to the aluminum solid solution in titania. α-Al2O3 and Al2TiO5 were observed at AlCl3/TiCl4 ratios higher than 1.1 and reactor temperatures in excess of 1400 °C. The rutile content, which increased with increasing Al/Ti ratio and residence time, was at a maximum at about 1200 °C and decreased at both lower and higher reactor temperatures.
Co-reporter:Shuisheng Sun;Chunzhong Li;Ling Zhang;HL Du;JS Burnell-Gray
Polymer International 2006 Volume 55(Issue 2) pp:
Publication Date(Web):5 DEC 2005
DOI:10.1002/pi.1932
The effects of particle size and surface treatment of CaCO3 particles on the microstructure and mechanical properties of poly(vinyl chloride) (PVC) composites filled with CaCO3 particles via a melt blending method were studied by SEM, an AG-2000 universal material testing machine and an XJU-2.75 Izod impact strength machine. The tensile and impact strengths of CaCO3/PVC greatly increased with decreasing CaCO3 particle size, which was attributed to increased interfacial contact area and enhanced interfacial adhesion between CaCO3 particles and PVC matrix. Titanate-treated nano-CaCO3/PVC composites had superior tensile and impact strengths to untreated or sodium-stearate-treated CaCO3/PVC composites. The impact strength of titanate-treated nano-CaCO3/PVC composites was 26.3 ± 1.1 kJ m−2, more than three times that of pure PVC materials. The interfacial adhesion between CaCO3 particles and PVC matrix was characterized by the interfacial interaction parameter B and the debonding angle θ, both of which were calculated from the tensile strength of CaCO3/PVC composites. Copyright © 2005 Society of Chemical Industry
Co-reporter:Baozhu Tian, Chunzhong Li, Feng Gu, Haibo Jiang, Yanjie Hu, Jinlong Zhang
Chemical Engineering Journal (15 August 2009) Volume 151(Issues 1–3) pp:220-227
Publication Date(Web):15 August 2009
DOI:10.1016/j.cej.2009.02.030
V-doped TiO2 (V–TiO2) nanoparticles were prepared by a simple one-step flame spray pyrolysis (FSP) technique. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR) spectra, UV–vis absorption spectroscopy, and nitrogen adsorption–desorption methods. Benefiting from the short residence time and high quenching rate during the flame spray process, V4+ ions are successfully incorporated into the crystal lattice of TiO2. It reveals that V doping favors the primary particle size growth as well as the increase of rutile content in the products. The photocatalytic activity of the V–TiO2 samples under UV and visible light irradiation were evaluate by the photocatalytic degradation of methylene blue (MB) and 2,4-dichlorophenol (2,4-DCP), respectively. It was found that V doping enhances the photocalytic activity under both UV and visible light irradiation. Especially, under visible light irradiation, the degradation rate of 2,4-dichlorophenol over 1%V–TiO2 is two times higher than that over undoped TiO2. The photocatalytic mechanisms for V–TiO2 samples under UV and visible light irradiation were tentatively discussed.
Co-reporter:Yin Zhao, Chunzhong Li, Xiuhong Liu, Feng Gu, H.L. Du, Liyi Shi
Applied Catalysis B: Environmental (1 March 2008) Volume 79(Issue 3) pp:208-215
Publication Date(Web):1 March 2008
DOI:10.1016/j.apcatb.2007.09.044
Co-reporter:Mengting Chen, Tao Tao, Ling Zhang, Wei Gao and Chunzhong Li
Chemical Communications 2013 - vol. 49(Issue 16) pp:NaN1614-1614
Publication Date(Web):2013/01/04
DOI:10.1039/C2CC38290C
We have manufactured a highly conductive and stretchable composite by backfilling a preformed graphene/MWCNT aerogel with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 2.8 S cm−1 with only 1.3 wt% graphene/MWCNT loading, and remains constant after 100 times repeated stretching by 20% and 5000 times bending.
Co-reporter:Zongnan Deng, Yanjie Hu, Dayong Ren, Shaoliang Lin, Hao Jiang and Chunzhong Li
Chemical Communications 2015 - vol. 51(Issue 72) pp:NaN13841-13841
Publication Date(Web):2015/07/21
DOI:10.1039/C5CC05069C
The reciprocal hybridization of MoO2 nanoparticles and few-layer MoS2 has been realized via a facile hydrothermal reaction. The resulting MoO2/MoS2 hybrids exhibit a high reversible specific capacity of 1103 mA h g−1 at 0.2 A g−1 with a high rate performance (273 mA h g−1 at 6.4 A g−1) and an excellent cycling stability (∼92% capacity retention after 800 cycles) mainly due to the strong synergistic effect between them.
Co-reporter:Xiaoyu Hou, Yanjie Hu, Hao Jiang, Junchao Huo, Yunfeng Li and Chunzhong Li
Journal of Materials Chemistry A 2013 - vol. 1(Issue 44) pp:NaN13820-13820
Publication Date(Web):2013/09/10
DOI:10.1039/C3TA12533E
Branch-type SnO2 nanowires with high crystallinity have been successfully prepared by a rapid and continuous flame spray pyrolysis (FSP) route. The SnO2 branch has an average diameter of 15–20 nm and a length of 200–700 nm. As is known, this is the first time one dimensional SnO2 nanowires with branch-type nanostructures have been synthesized using flame synthesis. The average growth rate of nanowires could reach 1 μm s−1, which is thousand times faster than other methods. Interestingly, it is found that Au nanoclusters appear at the tip of SnO2 nanowires. An in situ Au-catalyzed vapour–liquid–solid (VLS) model is proposed to explain the growth mechanism of branch-type SnO2 nanowires in flame. As photoanodes, the DSSCs based on branch-type SnO2 nanowires (with TiCl4 post-treatment) show a higher short-circuit current (JSC = 10.60 mA cm−2) and a superior power conversion efficiency of 4.23%, improved by 99.5% compared to pure SnO2 nanoparticles (2.12%). The efficiency improvement could be attributed to the unique branch-type nanowire architecture, which provides a highly efficient electron channel and excellent ability of light scattering.
Co-reporter:Hao Jiang, Jan Ma and Chunzhong Li
Chemical Communications 2012 - vol. 48(Issue 37) pp:NaN4467-4467
Publication Date(Web):2012/03/19
DOI:10.1039/C2CC31418E
We demonstrate a simple and scalable strategy for synthesizing hierarchical porous NiCo2O4 nanowires which exhibit a high specific capacitance of 743 F g−1 at 1 A g−1 with excellent rate performance (78.6% capacity retention at 40 A g−1) and cycling stability (only 6.2% loss after 3000 cycles).
Co-reporter:Junchao Huo, Yanjie Hu, Hao Jiang, Wenjuan Huang and Chunzhong Li
Journal of Materials Chemistry A 2014 - vol. 2(Issue 22) pp:NaN8272-8272
Publication Date(Web):2014/03/04
DOI:10.1039/C4TA00083H
Novel SnO2 nanorod@TiO2 hybrid materials have been designed and synthesized by in situ coating a layer of TiO2 on the surface of the SnO2 nanorods using a modified flame spray pyrolysis (FSP) approach. The as-prepared SnO2 nanorod@TiO2 hybrid materials have a length of up to about 150 nm and a diameter of about 40 nm. TiO2 is uniformly coated on well-crystallized SnO2 nanorods with a thickness of about 10 nm. The dye-sensitized solar cell (DSC) properties of the SnO2 nanorod@TiO2 hybrid materials were investigated. Owing to the superior light scattering effect, advantages of suppression charge recombination, and increased dye loading, the power conversion efficiency (η) of the SnO2 nanorod@TiO2 hybrid material electrode is 6.98%, much higher than that of the SnO2 nanorods electrode (3.95%) and P25 electrode (5.27%).
Co-reporter:Peng Zhao, Jing Zhang, Yihua Zhu, Xiaoling Yang, Xin Jiang, Yuan Yuan, Changsheng Liu and Chunzhong Li
Journal of Materials Chemistry A 2014 - vol. 2(Issue 47) pp:NaN8377-8377
Publication Date(Web):2014/10/03
DOI:10.1039/C4TB01445F
A highly efficient multifunctional nanoplatform for dual-modal luminescence imaging and pH-responsive drug delivery has been developed on the basis of a facile and novel strategy by covalently binding up-conversion (UC) luminescent NaYF4:Yb,Er nanoparticles with down-conversion (DC) fluorescent AgInS2–ZnS quantum dots. Due to the enriched carboxylic groups in the polymer shell of UC nanoparticles, the as-prepared nanocomposites (NCs) are water-soluble, functionalizable and able to load anti-cancer drug molecules, doxorubicin (DOX), by simple physical adsorption. The release of DOX from NCs was controlled by varying the pH, with an increased drug dissociation rate in an acidic environment, favorable for controlled drug release. Moreover, the endocytosis and the efficient drug release properties of the system were confirmed by luminescence microscopy. Hence, this approach provides a valuable method for fabricating a NC system with highly integrated functionalities for dual-modal luminescence cell imaging and targeted cancer therapy.
Co-reporter:Xin Jiang, Xiaoling Yang, Yihua Zhu, Yifan Yao, Peng Zhao and Chunzhong Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 5) pp:NaN2369-2369
Publication Date(Web):2014/12/05
DOI:10.1039/C4TA05913A
A novel hierarchical nanostructure composed of carbon coated Fe3O4 nanoparticles with seed-like morphology distributed on graphene (denoted as G/Fe3O4@C) is prepared as a high-capacity anode electrode for LIBs. β-FeOOH nanoseeds were first assembled on graphene by solvothermal treatment, followed by coating β-FeOOH nanoseeds with polydopamine via immersion in dopamine aqueous solution. Finally, G/Fe3O4@C is obtained after in situ phase transformation of β-FeOOH into Fe3O4 and simultaneous carbonization of the polydopamine nanocoating through thermal annealing at 500 °C. The thickness of the uniform and continuous carbon layer can be easily tailored by varying the polymerization time and the concentration of dopamine to balance the concurrent needs for high active material content and structural stability. The carbon layer can effectively prevent the agglomeration of Fe3O4 nanoparticles, which enables the reversible conversion reaction between Fe3O4 and lithium, and significantly improves the mechanical stability of electrodes by accommodating volume expansion of Fe3O4 nanoparticles during the electrochemical cycling. Meanwhile, the combination of graphene and the carbon shell improves the electrochemical reaction kinetics of the electrode. As a result, the obtained G/Fe3O4@C nanocomposites with the optimal carbon shell thickness of about 1.2 nm exhibit high reversible capacities with remarkable cyclic retention at different current rates (1344 mA h g−1 after cycling at 0.5 C for 200 cycles, 743 mA h g−1 after further cycling at 2 C for another 200 cycles) and excellent rate performance (150 mA h g−1 at 20 C) as anodes in lithium ion batteries.
Co-reporter:Yanyan Liu, Hongliang Jiang, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Journal of Materials Chemistry A 2016 - vol. 4(Issue 5) pp:NaN1701-1701
Publication Date(Web):2016/01/06
DOI:10.1039/C5TA10551J
The development of efficient and cheap bifunctional oxygen electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) to be applied in rechargeable metal–air batteries and unitized generative fuel cells (URFCs) operated with alkaline electrolytes is highly crucial and challenging. Here we report high-performance bifunctional electrocatalysts of transition metal nanoparticles encapsulated in nitrogen-doped carbon nanotubes (M/N-CNTs, M = Fe, Co, and Ni). The optimized Co/N-CNT hybrid shows the highest efficient bifunctional catalytic activity and excellent stability towards both the ORR and OER. The oxygen electrode activity parameter ΔE (the criteria for judging the overall catalytic activity of bifunctional electrocatalysts) value for Co/N-CNTs is 0.78 V, which surpasses those of Pt/C and RuO2 catalysts and most of the non-precious metal based bifunctional electrocatalysts reported in the previous literature studies. Furthermore, excellent long-term catalytic durability holds great promise in fields of renewable energy applications.
Co-reporter:Jianhua Shen, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Journal of Materials Chemistry A 2012 - vol. 22(Issue 26) pp:NaN13347-13347
Publication Date(Web):2012/05/16
DOI:10.1039/C2JM31998E
We have demonstrated a sandwich-structured Fe3O4/SiO2/Au/TiO2 photocatalyst, which shows magnetic separability, selective absorption and photocatalysis activity, and high efficiency, in catalyzing the decomposition of organic compounds under illumination of visible-light and simulated sunlight. The structural design of the photocatalyst takes advantage of the dense, homogeneous structure and the AuNPs content (ca. 4 nm, 1.63 wt%), which is prepared by a simple method. It possesses high efficiency visible-light photocatalytic activity due to the stable from nonmetal-doping and the plasmonic metal decoration, which enhances light harvesting and charge separation, and the small grain size of the anatase nanocrystals, which reduces the exciton recombination rate. More importantly, the catalyst is synthesized by a combination of plasmonic metal decoration of TiO2 nanocrystals with exposed {001} facets, and the selective adsorption and photocatalytic decomposition of azo dyes is accomplished by design of the surface chemistry. Additionally, these sandwich-structured photocatalysts can be applied to other catalytic system such as dye decoloration, water decomposition, hydrogen generation, and so on.
Co-reporter:Jianfei Huang, Huailong Li, Yihua Zhu, Qilin Cheng, Xiaoling Yang and Chunzhong Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 16) pp:NaN8741-8741
Publication Date(Web):2015/03/16
DOI:10.1039/C5TA00847F
Commercial copper foams have been tailored by a highly scalable method combining room-temperature wet-chemical etching and hydroxide thermolysis into a three-dimensional copper oxide nanowire array–copper (3D-CuONA–Cu) composite with macroporous voids and large-area fur-like nanowire array structures, whose structures and compositions were studied employing electron microscopy, X-ray diffraction (XRD) and Raman spectroscopy. The 3D-CuONA–Cu composite monolith was used as a free-standing electrode for pseudo-capacitive energy storage and enzyme-free H2O2 detection. Thanks to the 3D electrode architecture and the high-density in situ formed electroactive nanoarrays, an enhanced capacitance of 608 mF cm−2 at 2 mV s−1 was achieved, with an 88.6% capacity retention after 4000 cycles observed at the high current density of 30 mA cm−2. For enzyme-free H2O2 sensing, an extraordinary sensitivity of 5.75 mA mM−1 cm−2 and a low detection limit of 0.56 μM were achieved. This prototype sensor also exhibited eligible selectivity and feasibility for real sample analysis.
Co-reporter:Wei Shao, Feng Gu, Lili Gai and Chunzhong Li
Chemical Communications 2011 - vol. 47(Issue 17) pp:NaN5048-5048
Publication Date(Web):2011/03/25
DOI:10.1039/C1CC10548E
Hierarchical anatase TiO2 nanoplates with tunable shell structure were developed as the novel planar scattering layer in dye-sensitized solar cells, showing improved cell performance due to the enhanced light harvesting capability.
Co-reporter:Xiaoyu Hou, Yanjie Hu, Hao Jiang, Yunfeng Li, Xiaofeng Niu and Chunzhong Li
Chemical Communications 2015 - vol. 51(Issue 91) pp:NaN16376-16376
Publication Date(Web):2015/09/10
DOI:10.1039/C5CC06123G
Sn@Ni3Sn4 embedded nanocable-like carbon hybrids have been successfully prepared through a novel gas-phase route. The introduced Ni3Sn4 layer not only suppresses the tin-induced volume expansion, but also provides more voids and vacancies in the interior of the nanocables. When used as the anode in LIBs, the Sn@Ni3Sn4/C hybrids exhibit a long cycle life (360 mA h g−1 at 1 A g−1 after 1500 cycles).
Co-reporter:Xiaoming Lv, Yihua Zhu, Hongliang Jiang, Hua Zhong, Xiaoling Yang and Chunzhong Li
Dalton Transactions 2014 - vol. 43(Issue 40) pp:NaN15118-15118
Publication Date(Web):2014/08/13
DOI:10.1039/C4DT02245A
A novel and facile strategy has been successfully developed to synthesize uniform gold@titanium dioxide octahedral nanocages (Au@TiO2), which have a well-defined double-shelled structure with Au as the internal shell and TiO2 as the external shell. The unique Au@TiO2 double-shelled octahedral nanocages were elaborately fabricated by a Cu2O-templated strategy combining with spatially confined galvanic replacement. The formation process of these delicate hierarchical octahedral architectures is discussed in detail. The catalytic performance of the Au@TiO2 double-shelled octahedral nanocages was investigated using the reduction of 4-nitrophenol as a model reaction. The mesoporous structure of both the Au and TiO2 shells provides direct access for the reactant molecules to diffuse and subsequently interact with the Au shell. This novel catalyst shows excellent and stable activity for the catalytic reduction of 4-nitrophenol, which can be recycled for ten successive cycles of the reaction with a conversion efficiency of more than 90%. The superior catalytic activity attributes to mesoporous double shells, enhanced synergistic effects between the Au and TiO2 shells and the unique properties of the octahedral structure. More importantly, the as-obtained Au@TiO2 double-shelled octahedral nanocages also show potential applications in solar cells, organocatalysis and water splitting.
Co-reporter:Hao Jiang, Ting Sun, Chunzhong Li and Jan Ma
Journal of Materials Chemistry A 2012 - vol. 22(Issue 6) pp:
Publication Date(Web):
DOI:10.1039/C1JM14732C
Co-reporter:Shunan Zhao, Jianfei Huang, Yanyan Liu, Jianhua Shen, Hao Wang, Xiaoling Yang, Yihua Zhu and Chunzhong Li
Journal of Materials Chemistry A 2017 - vol. 5(Issue 8) pp:NaN4214-4214
Publication Date(Web):2017/01/23
DOI:10.1039/C6TA10749D
In this study, excellent full water splitting achieved with a rationally structured multimetallic Ni–Mo/Cu nanowire free-standing electrode prepared via scalable electrochemistry is reported. By combining a conductive nanostructured scaffold and highly active outer layers, the as-prepared Ni–Mo/Cu nanowires deliver superior hydrogen and oxygen evolution performance. To achieve a 20 mA cm−2 catalytic current in a 1 M KOH electrolyte, the NM-CNW requires an overpotential of only 152 mV for hydrogen evolution and 280 mV for oxygen evolution. When assembled into a full electrolyzer, the Ni–Mo/Cu nanowires can drive full water splitting at nearly 100% faradaic efficiency steadily up to 12 h without any significant performance decay, and afford a catalytic current close to that of the state-of-the-art Pt–RuO2 system over long-term operation.
Co-reporter:Haiyan Wang, Hao Jiang, Yanjie Hu, Neng Li, Xiujian Zhao and Chunzhong Li
Journal of Materials Chemistry A 2017 - vol. 5(Issue 11) pp:NaN5389-5389
Publication Date(Web):2017/02/06
DOI:10.1039/C7TA00030H
The exploitation of high-capacity and long-life MoS2-based materials is highly important for developing lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Herein, we demonstrate the confined synthesis of 2D MoS2/polyaniline (MoS2/PANI) nanosheet heterostructures with well-defined interfaces, in which the interlayer distance of MoS2 is greatly enlarged from 0.62 nm to 1.08 nm. The introduction of such a big interlayer distance for efficient Li+/Na+ storage has never been demonstrated before. The unique MoS2/PANI nanosheets can address well the key challenges of traditional MoS2 anode materials related to low conductivity particularly in the vertical direction, easy restacking/aggregation, large volumetric change and sluggish Li+/Na+ diffusion kinetics in the interlamination. Consequently, they deliver a high reversible capacity, superior rate capability and long cycle life for both LIBs and SIBs. A state-of-the-art ab initio molecular dynamics (AIMD) simulation also reveals that MoS2/PANI nanosheets with enlarged interlayer spacing possess a remarkably improved Li+/Na+ diffusion mobility compared to pristine MoS2 nanosheets. The present material design concept opens new directions for finding efficient LIBs/SIBs anodes with high capacity, rate capability and stability.
Co-reporter:Feng Gu, Lili Gai, Wei Shao, Chunzhong Li and Lukas Schmidt-Mende
Chemical Communications 2011 - vol. 47(Issue 29) pp:NaN8402-8402
Publication Date(Web):2011/06/24
DOI:10.1039/C1CC12309B
A seeded heteroepitaxial growth of ZnO nanorods selectively on TiO2 nanorod tips was achieved by restricting crystal growth on highly hydrophobic TiO2 nanorod film surfaces. Intriguing light harvesting performance and efficient charge transport efficiency has been found, which suggest potential applications in photovoltaics and optoelectronics.
Co-reporter:Hao Jiang, Ting Zhao, Chunzhong Li and Jan Ma
Chemical Communications 2011 - vol. 47(Issue 30) pp:NaN8592-8592
Publication Date(Web):2011/06/27
DOI:10.1039/C1CC12942B
Functional mesoporous carbon nanotubes (MCNTs) and their integration in situ with Pt nanocrystals (Pt/MCNTs) have been designed and successfully developed via a facile route, which exhibited enhanced performances in energy storage and conversion applications.
Co-reporter:Jianhua Shen, Yihua Zhu, Cheng Chen, Xiaoling Yang and Chunzhong Li
Chemical Communications 2011 - vol. 47(Issue 9) pp:NaN2582-2582
Publication Date(Web):2010/12/21
DOI:10.1039/C0CC04812G
A facile hydrazine hydrate reduction of graphene oxide (GO) with surface-passivated by a polyethylene glycol (PEG) method for the fabrication of graphene quantum dots (GQDs) with frequency upconverted emission is presented. And we speculate on the upconversion luminescence due to the anti-Stokes photoluminescence (ASPL), where the δE between the π and σ orbitals is near 1.1 eV.
Co-reporter:Hao Jiang, Junqing Hu, Feng Gu, Wei Shao and Chunzhong Li
Chemical Communications 2009(Issue 24) pp:
Publication Date(Web):
DOI:10.1039/B904408F
Co-reporter:Hao Jiang, Ting Zhao, Chunzhong Li and Jan Ma
Journal of Materials Chemistry A 2011 - vol. 21(Issue 11) pp:NaN3823-3823
Publication Date(Web):2011/01/24
DOI:10.1039/C0JM03830J
Uniform Ni(OH)2 hierarchical nanostructures, assembled from ultrathin nanoflakes with thickness of only ∼7.4 nm, are designed and investigated as electrochemical pseudo-capacitor materials for potential energy storage applications. The ultrathin nanostructures exhibit a highest specific capacitance of 1715 F g−1 at a scan rate of 5 mV s−1 within the potential range of 0.6 V with high rate capability and good cycling stability. The high specific capacitance and remarkable rate capability are promising for supercapacitor applications. To understand the effect of the microstructure on the properties, we also synthesized uniformly stacked Ni(OH)2 nanoplatelets (thickness of ∼22 nm) and randomly arranged hexagonal nanosheets (thickness of ∼140 nm). Both of the latter configurations exhibited good performance despite showing inferior properties compared to the uniform ultrathin Ni(OH)2 nanostructures. These results suggest the importance of rational design and synthesis of ultrathin nanomaterials for high-performance energy applications.
Co-reporter:Xiaoyu Hou, Yanjie Hu, Hao Jiang, Yunfeng Li, Wenge Li and Chunzhong Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 18) pp:NaN9988-9988
Publication Date(Web):2015/03/17
DOI:10.1039/C5TA01106J
SnOx nanocrystalline aggregates (NAs) encapsulated by an amorphous TiO2 layer have been successfully designed by a one-step flame spray pyrolysis (FSP). The synthesized SnOx NAs@TiO2 with different degrees of aggregations were composed of SnOx nanocrystallites ranging from 5 nm to 10 nm and a TiO2 layer with a thickness of 1–5 nm. The encapsulated TiO2 layer was introduced in situ by incorporating TiCl4 into the downstream of an FSP reactor, where TiO2 nucleated and grew in the surface of the SnOx NAs. The hydrolysis temperature of TiCl4 in a flame was controlled to synthesize amorphous TiO2 with intrinsic electrochemical features. As an anode in LIBs (Li-ion batteries), the SnOx NAs@TiO2 electrode showed superior cycle life and rate performance (capacity of 350 mA h g−1 after 300 cycles and 332 mA h g−1 at 1 A g−1) compared to pure SnOx or TiO2 electrodes. The remarkably enhanced Li+ storage performance is mainly attributed to the nanoscale of nanocrystalline aggregates, the core–shell structure of SnOx@TiO2 and the amorphous state of TiO2.
Co-reporter:Yihui Dai, Ling Chen, Vladimir Babayan, Qilin Cheng, Petr Saha, Hao Jiang and Chunzhong Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 42) pp:NaN21342-21342
Publication Date(Web):2015/09/14
DOI:10.1039/C5TA06958K
We demonstrate the synthesis of ultrathin MnO2 nanoflakes grown on N-doped carbon nanoboxes, forming an impressive hierarchical MnO2/C nanobox hybrid with an average size of 500 nm, which exhibits an excellent electrochemical performance due to the unique structure, N-doping and strong synergistic effects between them. In addition, we also assembled a green asymmetric supercapacitor (ASC) using the as-synthesized MnO2/C nanoboxes as a positive electrode and the corresponding N-doped carbon nanoboxes as a negative electrode in a neutral aqueous electrolyte, aiming to further enhance its energy density by extending the operating potential. More significantly, our ASC device is able to reversibly cycle within a wide operating voltage of 2.0 V and delivers a maximum energy density of 39.5 W h kg−1 with superior cycling stability (∼90.2% capacitance retention after 5000 cycles). These intriguing results show that hollow nanostructures will be promising electrode materials for advanced supercapacitors.
Co-reporter:Weina Chen, Hao Jiang, Yanjie Hu, Yihui Dai and Chunzhong Li
Chemical Communications 2014 - vol. 50(Issue 64) pp:NaN8859-8859
Publication Date(Web):2014/06/16
DOI:10.1039/C4CC02886D
Mesoporous single crystals Li4Ti5O12 grown on reduced graphene oxide (MSCs-LTO–rGO) nanohybrids have been synthesized by a simple hydrothermal reaction of TiO2/rGO and LiOH with subsequent annealing in Ar at 600 °C, which exhibited high specific capacity (171 mA h g−1) with much improved rate capability (132 mA h g−1 at 40 C) and intriguing cycling stability (85% capacity retention after 2000 cycles).
Co-reporter:Hao Jiang, Chunzhong Li, Ting Sun and Jan Ma
Chemical Communications 2012 - vol. 48(Issue 20) pp:NaN2608-2608
Publication Date(Web):2012/01/10
DOI:10.1039/C2CC18079K
Ni(OH)2/MnO2 core–shell nanowires with a nanoflake surface have been designed and synthesized, and can be applied not only in neutral electrolytes (355 F g−1, 70.4 wt% MnO2) but are also appropriate for alkaline electrolytes (487.4 F g−1, 35.5 wt% MnO2), with high cycling stability due to the synergistic effect between the core and shell.
Co-reporter:Xue Liu, Yanjie Hu, Guiqi Jia, Haoxuan Zhang, Hao Jiang and Chunzhong Li
Journal of Materials Chemistry A 2016 - vol. 4(Issue 31) pp:NaN12035-12035
Publication Date(Web):2016/07/07
DOI:10.1039/C6TA03335K
Rational construction of metal oxides-based electrode materials for Li-ion batteries (LIBs) is essential to simultaneously overcome their low conductivity and vulnerable nanostructure. Here, we demonstrate the design and synthesis of homologous V2O3/C box-in-box and V2O5 boxes as anodes and cathodes for all-nanobox based LIB full cells, which are subsequently obtained by thermal treatment in different atmospheres. While the V2O5 box cathodes can provide abundant active sites, short ionic diffusion distances and partial volume flexibility, the key design concept of the V2O3/C box-in-box is the carbon box-in-box, which further enhances the structural durability during lithiation/delithiation, hence giving rise to an extended lifespan. As proof-of-concept, the V2O3/C box-in-box anodes deliver a high reversible capacity of 641 mA h g−1 even after 1200 cycles at 1000 mA g−1, while the V2O5 box cathodes possess a specific capacity of 119 mA h g−1 at 10C with superior cycling stability. Importantly, a V2O3/C//V2O5 LIB full cell is assembled, which shows an impressive specific capacity of 97 mA h g−1 at 500 mA g−1 with a capacity retention of 81 mA h g−1 even after 100 cycles based on the cathode material weight.
Co-reporter:Hao Jiang, Jan Ma and Chunzhong Li
Journal of Materials Chemistry A 2012 - vol. 22(Issue 33) pp:NaN16942-16942
Publication Date(Web):2012/06/27
DOI:10.1039/C2JM33249C
We demonstrated the facile loading of ultrafine and loosened K-birnessite MnO2 floccules on the surface of polyaniline (PANI) nanofibers by simply soaking the polyaniline nanofibers in a KMnO4 aqueous solution for electrochemical energy storage applications. The as-prepared PANI–MnO2 coaxial nanofibers with optimal composition, when applied as an electrode, exhibited a high specific capacitance (383 F g−1 at 0.5 A g−1) with good rate and cycling stability in 1 M Na2SO4 aqueous solution. Such intriguing electrochemical performance is mainly attributed to the synergistic effects of the combined pseudo-capacitive contributions from the core and shell. The present findings promoted the development of advanced electrode materials, exhibiting huge potential for supercapacitors.
Co-reporter:Xin Jiang, Xiaoling Yang, Yihua Zhu, Hongliang Jiang, Yifan Yao, Peng Zhao and Chunzhong Li
Journal of Materials Chemistry A 2014 - vol. 2(Issue 29) pp:NaN11133-11133
Publication Date(Web):2014/05/08
DOI:10.1039/C4TA01348D
A three-dimensional (3D) foam architecture of ultrafine TiO2 nanoparticles embedded in N-doped graphene networks (denoted as UTO/NGF) is prepared via a facile hydrothermal self-assembly and a subsequent freeze-drying scheme. The obtained UTO/NGF possesses a large surface area, macro/mesoporous structure, and high-level nitrogen content (7.34%). Such a unique hierarchical architecture provides multidimensional electronic network, enlarged contact area between electrolyte and electrode, and numerous open channels for the access of the electrolyte, thus favoring diffusion kinetics for both electrons and lithium ions. Meanwhile, nitrogen doping can further improve the electrical conductivity and electrochemical activity of the obtained composite during electrochemical processes. As a consequence, the UTO/NGF exhibits high reversible capacities with remarkable cyclic retention at different current rates (165 mA h g−1 after 200 cycles at 1 C rate, 143 mA h g−1 after 200 cycles at 5 C rate) and excellent rate performance (96 mA h g−1 at 20 C) as anodes in lithium ion batteries.
Co-reporter:Jianhua Shen, Yunfeng Li, Yihua Zhu, Xiaoling Yang, Xiuzhong Yao, Jun Li, Guangjian Huang and Chunzhong Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 14) pp:NaN2882-2882
Publication Date(Web):2015/02/18
DOI:10.1039/C5TB00041F
The facile fabrication of Gd-labeled superparamagnetic Fe3O4 nanoparticles (NPs) and fluorescent CuInS2 (CIS) quantum dots conjugated with arginine-glycine-aspartic acid (RGD) peptides has been demonstrated, for tri-mode targeted T1-, T2-weighted magnetic resonance (MR) and fluorescence imaging of pancreatic cancer. The core–shell nanocomposites formed are water-dispersible, stable and biocompatible, as confirmed by MTT assay on BXPC-3 cells. Relaxivity measurements show a T1 relaxivity (r1) of 1.56 mM−1 s−1 and a T2 relaxivity (r2) of 23.22 mM−1 s−1, which enable T1- and T2-weighted MR imaging of cancer cells in vitro and in vivo. The MR imaging data clearly indicate that the multifunctional NPs can specifically target cancer cells with αvβ3 integrin over-expression on the cell surface, through a receptor-mediated delivery pathway. The T1-weighted positive and T2-weighted negative enhancement in the MR imaging significantly improves the diagnosis accuracy, and fluorescence imaging of tumor tissue can assist in clinical surgery. These findings suggest that these multifunctional NPs could be used as a platform for bimodal imaging (both MR and fluorescence) in various biological systems.
Co-reporter:Qi Yue, Hao Jiang, Yanjie Hu, Guiqi Jia and Chunzhong Li
Chemical Communications 2014 - vol. 50(Issue 87) pp:NaN13365-13365
Publication Date(Web):2014/09/11
DOI:10.1039/C4CC06733A
Mesoporous single-crystalline V2O5 nanorods assembled into novel hollow microspheres have been synthesized as cathode materials for lithium-ion batteries by a simple solvothermal treatment of NH4VO3 and ethylene glycol with subsequent annealing in air at 400 °C, which delivered a very high reversible capacity of 145.8 mA h g−1 at 2.5–4.0 V (vs. theoretical value: 147 mA h g−1) with much improved capacity retention and long cycle life at various rates.
Co-reporter:Jianhua Shen, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Chemical Communications 2012 - vol. 48(Issue 31) pp:NaN3699-3699
Publication Date(Web):2012/02/21
DOI:10.1039/C2CC00110A
Similar to the popular older cousins, luminescent carbon dots (C-dots), graphene quantum dots or graphene quantum discs (GQDs) have generated enormous excitement because of their superiority in chemical inertness, biocompatibility and low toxicity. Besides, GQDs, consisting of a single atomic layer of nano-sized graphite, have the excellent performances of graphene, such as high surface area, large diameter and better surface grafting using π–π conjugation and surface groups. Because of the structure of graphene, GQDs have some other special physical properties. Therefore, studies on GQDs in aspects of chemistry, physical, materials, biology and interdisciplinary science have been in full flow in the past decade. In this Feature Article, recent developments in preparation of GQDs are discussed, focusing on the main two approaches (top-down and bottom-down). Emphasis is given to their future and potential development in bioimaging, electrochemical biosensors and catalysis, and specifically in photovoltaic devices that can solve increasingly serious energy problems.
Co-reporter:Mengting Chen, Shasha Duan, Ling Zhang, Zhihui Wang and Chunzhong Li
Chemical Communications 2015 - vol. 51(Issue 15) pp:NaN3172-3172
Publication Date(Web):2014/12/15
DOI:10.1039/C4CC09367D
We have manufactured a highly conductive and stretchable composite by backfilling the 3D graphene–PEDOT:PSS skeleton with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 24 S cm−1 with only 1.5 wt% graphene and 1.5 wt% PEDOT:PSS loading, and its resistance increased only 35% when stretched to 80% strain.
