Co-reporter:Wenhai Wang;Dr. Long Kuai;Dr. Wei Cao; Dr. Marko Huttula;Sami Ollikkala;Taru Ahopelto;Ari-Pekka Honkanen; Simo Huotari;Mengkang Yu; Dr. Baoyou Geng
Angewandte Chemie International Edition 2017 Volume 56(Issue 47) pp:14977-14981
Publication Date(Web):2017/11/20
DOI:10.1002/anie.201708765
AbstractA mesoporous MnCo2O4 electrode material is made for bifunctional oxygen electrocatalysis. The MnCo2O4 exhibits both Co3O4-like activity for oxygen evolution reaction (OER) and Mn2O3-like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo2O4 is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred MnIV- and CoII-rich surface. The electrode material can be obtained on large-scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo2O4 could be used in metal–air batteries and/or other energy devices.
Co-reporter:Wenhai Wang;Dr. Long Kuai;Dr. Wei Cao; Dr. Marko Huttula;Sami Ollikkala;Taru Ahopelto;Ari-Pekka Honkanen; Simo Huotari;Mengkang Yu; Dr. Baoyou Geng
Angewandte Chemie 2017 Volume 129(Issue 47) pp:15173-15177
Publication Date(Web):2017/11/20
DOI:10.1002/ange.201708765
AbstractA mesoporous MnCo2O4 electrode material is made for bifunctional oxygen electrocatalysis. The MnCo2O4 exhibits both Co3O4-like activity for oxygen evolution reaction (OER) and Mn2O3-like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo2O4 is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred MnIV- and CoII-rich surface. The electrode material can be obtained on large-scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo2O4 could be used in metal–air batteries and/or other energy devices.
Co-reporter:Min Li;Haoran Du;Dr. Long Kuai;Kuangfu Huang;Yuanyuan Xia; Dr. Baoyou Geng
Angewandte Chemie International Edition 2017 Volume 56(Issue 41) pp:12649-12653
Publication Date(Web):2017/10/02
DOI:10.1002/anie.201707647
AbstractCarbon-based transition-metal oxides are considered as an appropriate anode material candidate for lithium-ion batteries. Herein, a simple and scalable dry production process is developed to produce carbon-encapsulated 3D net-like FeOx/C materials. The process is simply associated with the pyrolysis of a solid carbon source, such as filter paper, adsorbed with ferrite nitrate. The carbon derived from filter paper induces a carbothermal reduction to form metallic Fe, the addition of carbon and iron increase the conductivity of this material. As expected, this 3D net-like FeOx/C composite delivers an excellent charge capacity of 851.3 mAh g−1 after 50 cycles at 0.2 A g−1 as well as high stability and rate performance of 714.7 mAh g−1 after 300 cycles at 1 A g−1. Superior performance, harmlessness, low costs, and high yield may greatly stimulate the practical application of the products as anode materials in lithium-ion batteries.
Co-reporter:Kai Zhang, Wenhai Wang, Long Kuai, Baoyou Geng
Electrochimica Acta 2017 Volume 225(Volume 225) pp:
Publication Date(Web):20 January 2017
DOI:10.1016/j.electacta.2016.12.131
•A facile and efficient method to prepare NiFe-LDHs was presented.•Different Ni/Fe proportions of NiFe-LDH were synthesized.•The growth mechanism of this method has been discussed.•Ni6Fe4-LDH shows excellent OER performance in alkaline solution.•Chronopotentiometry curves only 0.08 V increased after 3 h’ continuous test.High-efficient catalysts for oxygen evolution reaction (OER) are crucial to energy storage and conversion between electricity and chemicals. This work proposes a facile co-reduction and subsequent co-oxidation strategy to gram-scale preparation of composition-controllable LDHs nanosheets by a case study of Ni-Fe LDHs. Different from the traditional coprecipitation method, this process does not need heating and pH control. More importantly, our method can make sure that the Ni-Fe proportion in the LDHs products is well consistent with that in the mother solution. Furthermore, the electrocatalytic OER results strongly demonstrate that the as-prepared Ni-Fe LDHs possess a top-scale activity toward OER in alkaline media, typically for the Ni6Fe4-LDH nanosheets with water oxidation overpotential as low as 0.24 V at a current density of 20 mA/cm2. Besides, it presents excellent stability during the endurance test. Therefore, the co-reduction and subsequent co-oxidation strategy is an highly efficient way to LDHs nanosheets for electrochemical applications.This work proposes a novel and facile co-reduction and subsequent co-oxidation strategy to gram-scale preparation of composition-controllable LDHs nanosheets with top-scale electrocatalytic activity toward OER in alkaline media.Download high-res image (161KB)Download full-size image
Co-reporter:Haoran Du;Chao Yuan;Kuangfu Huang;Wenhai Wang;Kai Zhang
Journal of Materials Chemistry A 2017 vol. 5(Issue 11) pp:5342-5350
Publication Date(Web):2017/03/14
DOI:10.1039/C6TA10327H
A mesoporous bowknot-like Co3O4 material has been synthesized through a facile hydrothermal method, using cobalt nitrate as the cobalt source, urea as the precipitator and gelatin as the guide agent, followed by calcination at 600 °C in air. Morphology characterization reveals that this bowknot-like Co3O4 material possesses a mesoporous structure consisting of nanoparticles. Electrochemical experiments illustrate that the mesoporous bowknot-like Co3O4 anode material exhibits a superior first and 100th reversible specific capacity of 1427.9 mA h g−1 and 1388.8 mA h g−1 at 0.2C, respectively. This material also delivers a high charge capacity of 751.3 mA h g−1 after 150 cycles at 2C. The novel preparation method and satisfactory performance make the bowknot-like Co3O4 a good candidate as a high-performance anode material for use in Lithium-Ion Batteries (LIBs).
Co-reporter:Qing Wang, Jing Geng, Chao Yuan, Long Kuai, Baoyou Geng
Electrochimica Acta 2016 Volume 212() pp:41-46
Publication Date(Web):10 September 2016
DOI:10.1016/j.electacta.2016.06.153
•Li4Ti5O12/TiO2 composites are synthesized by aerosol spraying hydrolysis-assisted method.•The composites demonstrate spherical mesoporous structure preferred for anode materials.•The capacity retention of the composites is 93.04% (145.27 mAh/g) after 120 cycles at 2C.•Excellent electrochemical performance is due to the special morphology and multiple components.Mesoporous spherical Li4Ti5O12/TiO2 composites have been synthesized by a facile aerosol spraying hydrolysis method following calcine at 600 °C for 8 h. The as-obtained samples were characterized by XRD, SEM, TEM, BET surface area, and XPS. The mesoporous spherical Li4Ti5O12/TiO2 exhibits superior electrochemical performance as an anode material for lithium-ion batteries than both the simple Li4Ti5O12 and non-porous Li4Ti5O12/TiO2. The discharge specific capacity of the mesoporous spherical Li4Ti5O12/TiO2 composite is 161, 143, and 111 mAh/g at 1C, 5C and 20C, respectively, and retains 93.04% (145.27 mAh/g) capacity after 120 cycles at 2C. Therefore, the as-obtained mesoporous spherical dual-phase Li4Ti5O12/TiO2 composite is potential to be applied as an efficient anode material for Li ion batteries.
Co-reporter:Peiyuan Zeng, Xiaoxiao Wang, Ming Ye, Qiuyang Ma, Jianwen Li, Wanwan Wang, Baoyou Geng and Zhen Fang
RSC Advances 2016 vol. 6(Issue 27) pp:23074-23084
Publication Date(Web):23 Feb 2016
DOI:10.1039/C5RA26176G
In this report, we present a facile method for the synthesis of porous MnCo2O4 nanorods. When the as-synthesized MnCo2O4 nanorods are applied as the anode material for lithium-ion batteries, they exhibit excellent electrochemical performance owing to their porous nature. Because of the delicate balance between structural stability and specific surface area, the porous MnCo2O4 nanorods show high discharge capacity and excellent cycling stability. The initial discharge capacity is 1845 mA h g−1 at a current density of 0.4 A g−1. Even being cycled at a current density of 30 A g−1, the discharge capacity is still about 533 mA h g−1. The effects of binders on the electrochemical performance of the electrode have also been investigated, showing that the CMC/SBR binder is more suitable than PVDF for the as-synthesized porous MnCo2O4 nanorods. The influences of the calcination temperature also have been systematically investigated, which suggest the electrochemical performance is determined by both the structural stability and surface area of the samples.
Co-reporter:Qiuyang Ma, Ming Ye, Peiyuan Zeng, Xiaoxiao Wang, Baoyou Geng and Zhen Fang
RSC Advances 2016 vol. 6(Issue 19) pp:15952-15959
Publication Date(Web):29 Jan 2016
DOI:10.1039/C5RA23885D
Amorphous GeOx hollow spheres with uniform particle size were prepared via a soft-template strategy using H2 bubbles as templates. The diameter of the hollow spheres can be controlled by using a micromolecular organic amine, and averages at 142 nm with a shell thickness of about 20 nm. The X-ray photoelectron spectroscopy data showed that the Ge:O stoichiometry ratio is 1:1.25. In the voltage window of 0.01–1.8 V, the discharge capacity of the amorphous GeOx hollow sphere was approximately 794 mA h g−1 at 500 mA g−1 after 100 cycles, demonstrating an excellent capacity retention and stability. In addition, even at different high current rates (2C, 4C), high specific capacities (857, 724 mA h g−1, respectively) can be achieved. The superior electrochemical performance of amorphous GeOx hollow spheres could be attributed to their unique porous hollow nanostructure and homogeneous particle size distribution, which not only enhance the specific capacity, but also alleviate the pulverization problems that prevent particle aggregation and facilitate better rate capabilities.
Co-reporter:Zhen Fang, Tingting Qiang, Jiaxin Fang, Yixuan Song, Qiuyang Ma, Ming Ye, Feiqiang Qiang, Baoyou Geng
Electrochimica Acta 2015 Volume 151() pp:453-458
Publication Date(Web):1 January 2015
DOI:10.1016/j.electacta.2014.11.063
Co-reporter:Tingting Qiang, Jiaxin Fang, Yixuan Song, Qiuyang Ma, Ming Ye, Zhen Fang and Baoyou Geng
RSC Advances 2015 vol. 5(Issue 22) pp:17070-17075
Publication Date(Web):02 Feb 2015
DOI:10.1039/C4RA16242K
Ge@C core–shell nanostructures were successfully synthesized by a facile n-hexane pyrogenation-reducing process. The Ge@C core–shell nanostructures exhibit excellent cycling performance and rate capability in comparison with pure Ge nanoparticles when used as an anode material for a lithium ion battery. The thin carbon shell endows the obtained Ge@C nanostructures with a high specific capacity of 985 mA h g−1 at a current density of 500 mA g−1 after 50 cycles. Furthermore, a discharge capacity of 850 mA h g−1 was observed at a current density of 4000 mA g−1. The excellent lithium storage performance can be attributed to the unique carbon shell structure. The carbon shell not only acts as the buffer layer to maintain structural stability during lithiation, but also increases electrical conductivity during the charge/discharge processes. The high rate capacity of the Ge@C nanostructures demonstrates it a promising anode material for high power lithium-ion batteries.
Co-reporter:Jing Geng;Long Kuai;Erjie Kan;Qing Wang ;Dr. Baoyou Geng
ChemSusChem 2015 Volume 8( Issue 4) pp:659-664
Publication Date(Web):
DOI:10.1002/cssc.201403222
Abstract
Abundant iron group metal oxides and their composites possess great potential in the application of electrochemical energy storage and conversion. In this work, we obtained Co–Fe–O composites/reduced graphene oxides (CFO/rGO) hybrid structures, engineered their compositions, phase, and structures by a facile hydrothermal route, and studied their composition-dependent activity for electrochemical oxygen evolution reaction (OER) in alkaline media. It is found that synergetic effects bring a clear decrease in overpotential and Tafel slope for CFO/rGO catalysts in comparison with monometallic composition/rGO catalysts. OER charge-transfer resistance is significantly reduced after Fe addition, indicating that the reaction barriers of CFO/rGO are reduced. The optimal CFO/rGO with Co–Fe ratio of 2:1 was identified. Our results on the synergetic effects of CFO/rGO enrich the understanding of iron-group composites for electrocatalytic applications.
Co-reporter:Lingxiao Wang;Jing Geng;Wenhai Wang;Chao Yuan;Long Kuai
Nano Research 2015 Volume 8( Issue 12) pp:3815-3822
Publication Date(Web):2015 December
DOI:10.1007/s12274-015-0881-0
Co-reporter:Yadong Liu, Zhen Fang, Long Kuai and Baoyou Geng
Nanoscale 2014 vol. 6(Issue 16) pp:9791-9797
Publication Date(Web):18 Jun 2014
DOI:10.1039/C4NR01470G
In this work, a general, facile, successive and eco-friendly method for multilayer nanostructures has been established for the first time. We take full advantage of the structural and compositional character of M1@M2 (M1 = Co, Ni, M2 = Pt/Pd, Pt, Pd and Au) core–shell nanostructures to prepare a series of reusable tremella-like M1@M2@M1(OH)2 three layer core–shell or yolk–shell nanocomposites with a magnetic core, a porous noble metal shell, and an ultrathin cobalt or nickel hydroxide shell. We evaluated their catalytic performance using a model reaction based on the reduction of 4-nitrophenol. These novel M1@M2@M1(OH)2 nanomaterials with a unique internal micro environment promoted the efficiency of the catalytic reaction, prolonged the service life of the catalyst and enhanced the overall activity of the catalyst in the catalytic process. The novel three layer core–shell nanocomposites can be extended to other applications such as biomedical detection, energy conversion and storage systems.
Co-reporter:Zhengcui Wu, Yaqin Wu, Tonghui Pei, Huan Wang and Baoyou Geng
Nanoscale 2014 vol. 6(Issue 5) pp:2738-2745
Publication Date(Web):29 Nov 2013
DOI:10.1039/C3NR05231A
Novel hierarchical heteronanostructures of ZnO nanorods/ZnS·(HDA)0.5 (HDA = 1,6-hexanediamine) hybrid nanoplates on a zinc substrate are successfully synthesized on a large scale by combining hydrothermal growth (for ZnO nanorods) and liquid chemical conversion (for ZnS·(HDA)0.5 nanoplates) techniques. The formation of ZnS·(HDA)0.5 hybrid nanoplates branches takes advantage of the preferential binding of 1,6-hexanediamine on specific facets of ZnS, which makes the thickening rate much lower than the lateral growth rate. The ZnS·(HDA)0.5 hybrid nanoplates have a layered structure with 1,6-hexanediamine inserted into interlayers of wurtzite ZnS through the bonding of nitrogen. The number density and thickness of the secondary ZnS·(HDA)0.5 nanoplates can be conveniently engineered by variation of the sulfur source and straightforward adjustment of reactant concentrations such as 1,6-hexanediamine and the sulfur source. The fabricated ZnO/ZnS·(HDA)0.5 heteronanostructures show improved electrochemical catalytic properties for hydrazine compared with the primary ZnO nanorods. Due to its simplicity and efficiency, this approach could be similarly used to fabricate varieties of hybrid heterostructures made of materials with an intrinsic large lattice mismatch.
Co-reporter:Zhengcui Wu, Huan Wang, Yejing Xue, Baoer Li and Baoyou Geng
Journal of Materials Chemistry A 2014 vol. 2(Issue 41) pp:17502-17510
Publication Date(Web):15 Aug 2014
DOI:10.1039/C4TA02989E
The surface modification of semiconductors is an important strategy for tuning solar-driven photocatalytic activity. Herein, ZnO nanorods/ZnSe heteronanostructure arrays with a tunable microstructure of the ZnSe shell, with a high visible light photocatalytic activity, are produced by liquid chemical conversion using ZnO nanorods arrays on a zinc foil. By varying the ammonia concentration, the secondary ZnSe shell can be formed of nanoparticles, nanorods and nanosheets, engineered by the oriented attachment of small ZnSe nanoparticles. By virtue of the synergistic advantages of the enhanced visible light adsorption capability and the effective separation of electron–hole pairs obtained by coupling ZnO nanorods with ZnSe nanostructures, the ZnO nanorods/ZnSe heteronanostructure arrays exhibit high visible light driven photocatalytic activities as well as shell microstructure dependent photocatalytic performances.
Co-reporter:Ronghui Que, Yucheng Huang, Qinling Li, Hong Yao, Baoyou Geng, and Mingwang Shao
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 22) pp:19752
Publication Date(Web):November 5, 2014
DOI:10.1021/am504777g
This work presents a method of generating electric current based on the defects of few-layer boron nitride nanosheets (BNNSs). The density functional theory calculations showed that the atomic charge of the B atom in acetone was more positive than in water. The electrostatic force microscopy measurements illustrated that the local electrical potential was 0.35 mV in acetone, while the potential signal was very difficult to capture when using water as the dispersant. This effect was further demonstrated by the performance of the acoustic energy-harvesting nanogenerator: the BNNSs were assembled into a film after being dispersed in acetone and then integrated into the generator device, generating average output current of ∼0.98 nA, which was much better than 0.2 nA, the average output current of another device with water as the dispersant. These results demonstrated that solvent effects made the as-prepared BNNSs carry net charges, which could be utilized to harvest acoustic energy and generate current.Keywords: acoustic energy; boron nitride nanosheets; defects; solvent effect
Co-reporter:Yan Sang, Long Kuai, Changyu Chen, Zhen Fang, and Baoyou Geng
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 7) pp:5061
Publication Date(Web):March 13, 2014
DOI:10.1021/am5002019
In this article, AgVO3@AgBr@Ag nanobelt heterostructures were fabricated as an efficient visible-light photocatalyst through a hydrothermal process, an anion-exchange reaction, and a light-induced reduction. SEM and TEM characterization revealed that anion exchange followed by light-induced reduction is an efficient method to synthesize well-dispersed AgBr@Ag nanoparticles on the surface of AgVO3 nanobelts. The composite photocatalyst efficiently combines visible-light active AgBr and AgVO3 with the surface plasmon resonance (SPR) effect of Ag nanoparticles. The obtained catalyst displayed a high performance for removing organic dye in the range of visible light. This improved visible-light response likely originates from a synergistic effect of the different components. This work provides a versatile approach for accessing efficient, stable, and recyclable visible-light-driven plasmonic photocatalysts.Keywords: AgVO3@AgBr@Ag; catalysis; heterostructures; ion exchange; plasmonic photocatalyst; visible-light induction;
Co-reporter:Hai-Sheng Lu, Linlu Bai, Wei-Wei Xiong, Peizhou Li, Junfeng Ding, Guodong Zhang, Tom Wu, Yanli Zhao, Jong-Min Lee, Yanhui Yang, Baoyou Geng, and Qichun Zhang
Inorganic Chemistry 2014 Volume 53(Issue 16) pp:8529-8537
Publication Date(Web):August 7, 2014
DOI:10.1021/ic5011133
In this report, three new metal–organic frameworks (MOFs), [Co3(μ3-OH)(HBTC)(BTC)2Co(HBTC)]·(HTEA)3·H2O (NTU-Z30), [Co(BTC)]·HTEA·H2O (NTU-Z31), [Co3(BTC)4]·(HTEA)4 (NTU-Z32), where H3BTC = 1,3,5-benzenetricarboxylic acid, TEA = triethylamine, and NTU = Nanyang Technological University, have been successfully synthesized under surfactant media and have been carefully characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, and IR spectromtry. NTU-Z30 has an unusual trimeric [Co3(μ3-OH)(COO)7] secondary building unit (SBU), which is different from the well-known trimeric [Co3O(COO)6] SBU. The topology studies indicate that NTU-Z30 and NTU-Z32 possess two new topologies, 3,3,6,7-c net and 2,8-c net, respectively, while NTU-Z31 has a known topology rtl type (3,6-c net). Magnetic analyses show that all three materials have weak antiferromagnetic behavior. Furthermore, NTU-Z30 has been selected as the heterogeneous catalyst for the aerobic epoxidation of alkene, and our results show that this material exhibits excellent catalytic activity as well as good stability. Our success in growing new crystalline cobalt 1,3,5-benzenetricarboxylate MOFs under surfactant media could pave a new road to preparing new diverse crystalline inorganic materials through a surfactant-thermal method.
Co-reporter:Yucheng Huang ; Chongyi Ling ; Hai Liu ; Sufan Wang
The Journal of Physical Chemistry C 2014 Volume 118(Issue 17) pp:9251-9260
Publication Date(Web):April 9, 2014
DOI:10.1021/jp5013158
First-principles calculations were employed to explore the electronic and magnetic properties of a two-dimensional (2D) SnSe2 monolayer sheet and its derived one-dimensional (1D) nanoribbons and nanotubes. The results unveiled that the semiconductor–metal or metal–semiconductor transition can be realized by subtly controlling the strain for all these nanostructures. Surprisingly, without introduction of impurities and the absence of transition metal atoms, a −10% compressive strain can induce magnetic behaviors in SnSe2 armchair nanoribbons and the emerged magnetic moment increases rapidly and linearly with the increase of strain. The magnetism is found to be stemmed from the nonmetallic anionic Se atom at the ribbon edge. The tunable electronic and magnetic properties can be well understood through the analysis of partial charge density distribution and partial density of states. It was found that the direction of applied strain is a determined factor that can affect the energy shift of Se p orbital, leading to different composition of the states near the Fermi level. Finally, the stabilities of these SnSe2 nanostructures were evaluated for the possibility of experimental realizations. We believe that our results will provide useful information for their potential applications in electromechanical nanodevices, which will stimulate further experimental and theoretical investigations in this field.
Co-reporter:Long Kuai;Jing Geng;Changyu Chen;Erjie Kan;Yadong Liu;Qing Wang ;Dr. Baoyou Geng
Angewandte Chemie International Edition 2014 Volume 53( Issue 29) pp:7547-7551
Publication Date(Web):
DOI:10.1002/anie.201404208
Abstract
An aerosol-spray-assisted approach (ASAA) is proposed and confirmed as a precisely controllable and continuous method to fabricate amorphous mixed metal oxides for electrochemical water splitting. The proportion of metal elements can be accurately controlled to within (5±5) %. The products can be sustainably obtained, which is highly suitable for industrial applications. ASAA was used to show that Fe6Ni10Ox is the best catalyst among the investigated Fe-Ni-Ox series with an overpotential of as low as 0.286 V (10 mA cm−2) and a Tafel slope of 48 mV/decade for the electrochemical oxygen evolution reaction. Therefore, this work contributes a versatile, continuous, and reliable way to produce and optimize amorphous metal oxide catalysts.
Co-reporter:Long Kuai;Jing Geng;Changyu Chen;Erjie Kan;Yadong Liu;Qing Wang ;Dr. Baoyou Geng
Angewandte Chemie 2014 Volume 126( Issue 29) pp:7677-7681
Publication Date(Web):
DOI:10.1002/ange.201404208
Abstract
An aerosol-spray-assisted approach (ASAA) is proposed and confirmed as a precisely controllable and continuous method to fabricate amorphous mixed metal oxides for electrochemical water splitting. The proportion of metal elements can be accurately controlled to within (5±5) %. The products can be sustainably obtained, which is highly suitable for industrial applications. ASAA was used to show that Fe6Ni10Ox is the best catalyst among the investigated Fe-Ni-Ox series with an overpotential of as low as 0.286 V (10 mA cm−2) and a Tafel slope of 48 mV/decade for the electrochemical oxygen evolution reaction. Therefore, this work contributes a versatile, continuous, and reliable way to produce and optimize amorphous metal oxide catalysts.
Co-reporter:Wenzheng Li, Long Kuai, Qing Qin and Baoyou Geng
Journal of Materials Chemistry A 2013 vol. 1(Issue 24) pp:7111-7117
Publication Date(Web):03 Apr 2013
DOI:10.1039/C3TA00106G
In this work, Ag–Au bimetallic nanostructures with various component ratios were successfully synthesized through a simple kinetic controlled co-reduction route at room temperature. The structure and composition of the as-obtained products has been adjusted and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDX) elemental mapping, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and UV-visible spectra. Meanwhile, Ag67.3Au32.7 bimetallic nanostructures were identified to show the best sensing performance in the enzyme-free detection of H2O2 with a short response time (<5 s) at an applied potential of −0.5 V, a linear range from 0.01 to 68 mM (R2 = 0.998) with a lower detection limit of 0.2 μM and higher sensitivity of 600 μA mM−1 cm−2. More importantly, the component-dependent electrochemical sensor data of different component nanostructures has been studied, and the synergistic effect between Ag and Au can lead to the best performance of H2O2 sensing. The interaction of diffusion and adsorption we raised reasonably has been used to explain the component-depended performance. Significantly, this work supplies an understanding of the bimetallic component effect for H2O2 sensing by the control of the components of the Ag–Au bimetal, and find out the Ag67.3Au32.7 bimetallic nanostructures are the most excellent candidate for enzyme-free H2O2 sensing.
Co-reporter:Lu Chen, Long Kuai and Baoyou Geng
CrystEngComm 2013 vol. 15(Issue 11) pp:2133-2136
Publication Date(Web):14 Jan 2013
DOI:10.1039/C3CE27058K
This paper describes the preparation of Pt nanorods by directly growing them on the surface of Au. Electrochemical measurements were performed to investigate their catalytic performance towards methanol oxidation. It was found from cyclic voltammetry that the Pt nanorods supported on Au nanoparticles had excellent steady-state catalytic activity and high catalytic activity for methanol electrooxidation. They also exhibited a slightly slower current decay over time.
Co-reporter:Shaozhen Wang;Long Kuai;Dr. Yucheng Huang;Xue Yu;Yadong Liu;Wenzheng Li;Lu Chen ;Dr. Baoyou Geng
Chemistry - A European Journal 2013 Volume 19( Issue 1) pp:240-248
Publication Date(Web):
DOI:10.1002/chem.201203398
Abstract
Herein we report a gentle seedless and surfactant-free method for the preparation of clean-surface porous platinum nanoparticles. In terms of electrocatalytic CH3OH oxidation, the clean-surface porous platinum exhibited better performance than platinum nanoparticles and a commercial Pt/C catalyst. The porous nanostructures exhibited 2.26-fold higher mass activity and 2.8-fold greater specific activity than the Pt/C catalyst. More importantly, three typical surfactants, cetyltrimethylammonium bromide/chloride (CTAB/C), poly(vinylpyrrolidone), and sodium dodecyl sulfate, were chosen to study the inhibition effect of surfactants on electrocatalytic performance. It was observed that the surfactants led to a clear selective decrease in electrocatalytic performance. CTAB/C inhibited the catalytic activity the most due to the stronger interaction between the OH-enriched platinum surface and the positively charged molecules. Thus, this work indicates that these clean-surface porous platinum nanoparticles may be used as efficient catalysts for direct methanol fuel cells and provides a greater understanding of the inhibition effects of surfactants on catalytic activity.
Co-reporter:Shaozhen Wang;Long Kuai;Dr. Yucheng Huang;Xue Yu;Yadong Liu;Wenzheng Li;Lu Chen ;Dr. Baoyou Geng
Chemistry - A European Journal 2013 Volume 19( Issue 1) pp:
Publication Date(Web):
DOI:10.1002/chem.201290226
Co-reporter:Lu Chen;Long Kuai;Xue Yu;Wenzheng Li ;Dr. Baoyou Geng
Chemistry - A European Journal 2013 Volume 19( Issue 35) pp:11753-11758
Publication Date(Web):
DOI:10.1002/chem.201301490
Abstract
Bimetallic tubular nanostructures have been the focus of intensive research as they have very interesting potential applications in various fields including catalysis and electronics. In this paper, we demonstrate a facile method for the fabrication of Au–Pt double-walled nanotubes (Au–Pt DWNTs). The DWNTs are fabricated through the galvanic displacement reaction between Ag nanowires and various metal ions, and the Au–Pt DWNT catalysts exhibit high active catalytic performances toward both methanol electro-oxidation and 4-nitrophenol (4-NP) reduction. First, they have a high electrochemically active surface area of 61.66 m2 g−1, which is close to the value of commercial Pt/C catalysts (64.76 m2 g−1), and the peak current density of Au–Pt DWNTs in methanol oxidation is recorded as 138.25 mA mg−1, whereas those of Pt nanotubes, Au/Pt nanotubes (simple mixture), and commercial Pt/C are 24.12, 40.95, and120.65 mA mg−1, respectively. The Au–Pt DWNTs show a markedly enhanced electrocatalytic activity for methanol oxidation compared with the other three catalysts. They also show an excellent catalytic performance in comparison with common Au nanotubes for 4-nitrophenol (4-NP) reduction. The attractive performance exhibited by these prepared Au–Pt DWNTs can be attributed to their unique structures, which make them promising candidates as high-performance catalysts.
Co-reporter:Yixing Ye, Long Kuai and Baoyou Geng
Journal of Materials Chemistry A 2012 vol. 22(Issue 36) pp:19132-19138
Publication Date(Web):02 Aug 2012
DOI:10.1039/C2JM33893A
This paper reported a facile template-free route to prepare hierarchical Fe3O4–Co3O4 yolk–shell nanostructures. These highly porous architectures, with a diameter of about 2 μm, were assembled from Co3O4 flower-like shells and Fe3O4 sphere core. A series of experiments with different conditions were carried out to determine the key factors in this typical solvothermal synthesis that led to the formation of the obtained yolk–shell nanostructures, and a possible growth mechanism was proposed. Sequentially, some other similar metal oxide nanostructures were also obtained in this way. Importantly, the obtained Fe3O4–Co3O4 yolk–shell nanostructures exhibit excellent electrocatalytic ORR performance. The half-wave potential of the yolk–shell nanostructures is about 5 and 80 mV positive-shifted compared to that of the independent Co3O4 and Fe3O4 nanoparticles. The current density of O2 reduction for the Fe3O4–Co3O4 yolk–shell nanostructures is also much higher than that of Co3O4 and Fe3O4 nanoparticles. The enhanced electrocatalytic performance for Fe3O4–Co3O4 yolk–shell nanostructures may make them available to be an efficient and cheap noble-metal free cathodic catalyst for PEMFCs.
Co-reporter:Xue Yu, Long Kuai and Baoyou Geng
Nanoscale 2012 vol. 4(Issue 18) pp:5738-5743
Publication Date(Web):26 Jul 2012
DOI:10.1039/C2NR31765F
Pt-based nanocomposites have been of great research interest. In this paper, we design an efficient MO/rGO/Pt sandwich nanostructure as an anodic electrocatalyst for DMFCs with combination of the merits of rigid structure of metallic oxides (MOs) and excellent electronic conductivity of reduced oxidized graphene (rGO) as well as overcoming their shortcomings. In this case, the CeO2/rGO/Pt sandwich nanostructure is successfully fabricated through a facile hydrothermal approach in the presence of graphene oxide and CeO2 nanoparticles. This structure has a unique building architecture where rGO wraps up the CeO2 nanoparticles and Pt nanoparticles are homogeneously dispersed on the surface of rGO. This novel structure endows this material with great electrocatalytic performance in methanol oxidation: it reduces the overpotential of methanol oxidation significantly and its electrocatalytic activity and stability are much enhanced compared with Pt/rGO, CeO2/Pt and Pt/C catalysts. This work supplies a unique MO/rGO/Pt sandwich nanostructure as an efficient way to improve the electrocatalytic performance, which will surely shed some light on the exploration of some novel structures of electrocatalyst for DMFCs.
Co-reporter:Nan Yu, Long Kuai, Qing Wang and Baoyou Geng
Nanoscale 2012 vol. 4(Issue 17) pp:5386-5393
Publication Date(Web):05 Jul 2012
DOI:10.1039/C2NR31055D
Pt-filled porous LaNiO3 cubes are prepared through a facile route. The characterizations reveal that large numbers of pores (9–10 nm) are distributed homogeneously in porous LaNiO3 cubes. The Pt nanoparticles residing in the pores of porous LaNiO3 cubes are about 5 nm in size. The investigation on the electrocatalytic activity reveals that electrocatalytic activity of the obtained Pt loaded porous LaNiO3 nanocubes exhibit a significantly improved electrochemical active surface area (EASA) and a remarkably enhanced electrocatalytic performance toward methanol oxidation. The results are significant for improving the efficiency of Pt-based catalysts for DMFCs as well as the applications of perovskite compounds.
Co-reporter:Baoyou Geng, Bo Tao, Xuelian Li and Wenjing Wei
Nanoscale 2012 vol. 4(Issue 5) pp:1671-1676
Publication Date(Web):17 Jan 2012
DOI:10.1039/C2NR12102F
Uniform porous three-dimensional nanoarchitectures of α-Fe2O3 with high yield have been synthesized by a route based on a Ni2+/surfactant system. The obtained α-Fe2O3 has a flue-like porous morphology with a rough surface. What is more, spatially ordered nodes and meshes are presented in these networks. By adjusting the experimental parameters such as temperature, reaction time, proportion of Ni2+/PVP and types of cation, we can control the morphology of the samples well. A possible formation mechanism is proposed to explain the growth of the flue-like nanostructures. The obtained flue-like porous α-Fe2O3 has a large specific surface area of 88.82 m2 g−1. It exhibits significantly enhanced visible-light-driven photocatalytic performance in the degradation of methylene blue, compared with α-Fe2O3 nanoparticles. This work not only enriches the synthesis methods of porous architectures, but also facilitates the applications of α-Fe2O3 in the fields of water treatment, sunlight utilization and so forth.
Co-reporter:Lizhen Zhou, Long Kuai, Wenzheng Li, and Baoyou Geng
ACS Applied Materials & Interfaces 2012 Volume 4(Issue 12) pp:6463
Publication Date(Web):November 27, 2012
DOI:10.1021/am302546d
In this letter, Au–CuxOS yolk–shell nanostructures with porous shell are prepared through a facile ion exchange route from Au@Cu2O core–shell nanostructures. The as-prepared yolk–shell nanostructures exhibit ultrasensitive enzyme-free detection of H2O2 molecules with higher sensitivity (50.41 μA μM–1) and lower detection limit (0.01 μM) as well with excellent anti-interference capacity in comparison with both hollow CuxOS nanospheres and Au nanoparticles. Therefore, the obtained Au–CuxOS yolk–shell nanostructures have potential application in ultralow concentration enzyme-free H2O2 detection for biomedicine diagnosis.Keywords: Au−CuxOS yolk−shell nanostructures; H2O2 detection; ion exchange;
Co-reporter:Yanyan Zhao, Long Kuai and Baoyou Geng
Catalysis Science & Technology 2012 vol. 2(Issue 6) pp:1269-1274
Publication Date(Web):20 Mar 2012
DOI:10.1039/C2CY20074K
Visible light-driven photocatalysts have attracted a great deal of attention for their direct use of solar energy. In this paper, an efficient and low-cost visible light-driven composite photocatalyst, comprising of Ag–AgBr/γ-Al2O3 nanostructures, has been facilely prepared by a surfactant-controlled precipitation–deposition and subsequent light-driven route. Hollow flower-like γ-Al2O3 nanostructures was chosen as the support. CTAB controlled the size of the deposited nanoparticles in both the Br source and the surfactant. The microstructures, surface chemical composition, visible light-driven photocatalytic performance and mechanism have been investigated systematically by SEM, TEM, XPS and so forth. The Ag–AgBr nanoparticles were distributed uniformly on the surface of the hollow flower-like γ-Al2O3 nanostructures, whose specific surface area value reached 116.5 m2 g−1. The Ag–AgBr/γ-Al2O3 composite nanostructures exhibit photocatalytic advantages over pure Ag–AgBr nanoparticles, such as decomposing aromatic compounds and organic dyes within several minutes of visible light irradiation. They also have good stabilities meaning the photocatalytic activity seldom decreases even when used 5 times under visible light irradiation. Meanwhile, the amount of Ag–AgBr needed and the cost decreases significantly. Thus, the as-prepared composite photocatalyst, consisting of Ag–AgBr/γ-Al2O3 nanostructures, will be an efficient and low-cost material for the removal of organic pollutants under visible light irradiation.
Co-reporter:Shaozhen Wang, Long Kuai, Xing Han and Baoyou Geng
CrystEngComm 2012 vol. 14(Issue 20) pp:6581-6585
Publication Date(Web):12 Jul 2012
DOI:10.1039/C2CE25634G
Multi-twinned Au nanostructures expose more corners and edges than other usual nanostructures. In addition, there are many defects on the surface of the multi-twinned nanostructures, so that they can supply many active sites for electrocatalytic reactions. This paper reports unusual branched twinned Au nanostructures in a facile hydrothermal reduction system based on theoretical analysis and experimental exploring. According to the time-dependent and relative experiments, an etching/re-crystallization growth mechanism is proposed. Besides, the electrochemical investigations suggests that the branched twinned Au nanostructures exhibit enhanced electrocatalytic ORR performance in alkaline media compared with sphere-like Au nanoparticles, because of the higher chemical activity of the corner, edge atoms and defects. Namely, the reduction peak potential of O2 is positive-shifted by 48 mV compared with Au nanoparticles, and the reduction peak current density is 1.45 times that of the Au nanoparticles. Thus, our work enriches the theoretical study of twinned noble metallic nanostructures and accelerates the development of cathodic electrocatalysts for alkaline fuel cells.
Co-reporter:Chunhua Wang, Yixing Ye, Bo Tao and Baoyou Geng
CrystEngComm 2012 vol. 14(Issue 10) pp:3677-3683
Publication Date(Web):28 Feb 2012
DOI:10.1039/C2CE06707B
Twinned-hemisphere-like CuO architectures with sizes ranging from 2 to 2.5 μm have been successfully prepared via a simple hydrophilic polymer-assisted hydrothermal route. The morphology of CuO is greatly affected by the mass ratio of Cu(CH3COO)2·H2O:PSS and the quantities of NaF. The different morphological products, such as spheres, twinned-hemispheres and sheets, have been obtained by changing the reaction conditions, which have been discussed in detail in this paper. The as-obtained products were characterized by SEM, XRD, FT-IR and BET. The adsorption capacity of the twinned-hemisphere product was detected by UV–vis spectroscopy. It was found that the as-obtained CuO twinned-hemispheres show high selectivity and short removal times to separate dyes from wastewater with a low cost and no secondary pollution.
Co-reporter:Jie Yang, Baoyou Geng, Yixing Ye and Xue Yu
CrystEngComm 2012 vol. 14(Issue 8) pp:2959-2965
Publication Date(Web):22 Feb 2012
DOI:10.1039/C2CE06532K
In this paper, MTiO3 (M = Sr, Ba, and Ca) perovskite polyhedra have been successfully synthesized through a facile hydrothermal route, in which appropriate amounts of metal salts and sodium hydroxide are mixed with the stick-like titania powders to fabricate the products. Cubic SrTiO3, dodecahedral BaTiO3, and cross-shaped CaTiO3 perovskites are finally obtained. The experimental conditions have also been investigated in detail and a feasible growth mechanism is proposed to illustrate the formation of MTiO3 perovskites. Furthermore, we demonstrate the possibility of the method, in which titania nanorods act as the precursor, to produce titanate compounds with a unique morphology. This work not only enriches the synthesis methods of MTiO3 perovskites, but also facilitates the study of potential applications of titanate perovskite compounds.
Co-reporter:Bo Tao, Qian Zhang, Zezhong Liu, Baoyou Geng
Materials Chemistry and Physics 2012 Volume 136(2–3) pp:604-612
Publication Date(Web):15 October 2012
DOI:10.1016/j.matchemphys.2012.07.033
Ring-like materials have attracted intense research interests because of their intriguing structural features and promising applications. In this work, we report an effective solvothermal method to prepare single-crystalline α-Fe2O3 nanorings with different morphologies without using any templates. Hexagonal nanorings and circular nanorings have been obtained just by varying the pH of initial solution with HCl or NaOH. On the basis of a series of experiments and characterizations, the growth mechanism of these kinds of nanorings is explained by the influence of the pH values and different anionic ligands. Here the cooperative action of the VO43− and SO42−, involving adsorption and coordination, is a crucial factor in bringing about the formation of the ring-like structures.Graphical abstractSingle-crystalline α-Fe2O3 nanorings with different morphologies are successfully fabricated. The growth mechanism involving crystallization, Ostwald ripening and subsequent oriented dissolution is proposed to illustrate the formation of the ring-like structures.Highlights► Single-crystalline α-Fe2O3 nanorings were synthesized by a solvothermal approach. ► The cooperative action of the VO43− and SO42− is a crucial factor in the formation of the ring-like structures. ► The Hc value of circular nanorings is larger than that of the hexagonal ones.
Co-reporter:Long Kuai, Xue Yu, Shaozhen Wang, Yan Sang, and Baoyou Geng
Langmuir 2012 Volume 28(Issue 18) pp:7168-7173
Publication Date(Web):April 13, 2012
DOI:10.1021/la300813z
It is a known fact that Pd-based bimetallic nanostructures possess unique properties and excellent catalytic performance. In this work, the Au–Pd alloy and core–shell nanostructures have been prepared by a simple one-pot hydrothermal coreduction route, and their formation process and mechanism are discussed in detail. A reducing capacity-induced controlled reducing mechanism is proposed for the formation process of Au–Pd bimetallic nanostructures. CTAB plays a key role in the formation of alloy Au–Pd nanostructures. When CTAB is absent, the products are typical core–shell nanostructures. Moreover, the as-prepared nanostructures exhibit excellent electrocatalytic ORR performance in alkaline media, especially for Au–Pd alloy nanostructures. The overpotential of oxygen reduction gets reduced significantly, and the peak potential is positive-shifted by 44 and 34 mV in comparison with the core–shell ones and Pd/C catalyst, respectively. Thus, the controllable preparation and excellent electrocatalytic properties will make them become a potentially cheaper Pd-based cathodic electrocatalyst for DAFCs in alkaline media.
Co-reporter:Long Kuai;Dr. Baoyou Geng;Shaozhen Wang ;Yan Sang
Chemistry - A European Journal 2012 Volume 18( Issue 30) pp:9423-9429
Publication Date(Web):
DOI:10.1002/chem.201200893
Abstract
In this work, we utilize the galvanic displacement synthesis and make it a general and efficient method for the preparation of AuM (M=Au, Pd, and Pt) core–shell nanostructures with porous shells, which consist of multilayer nanoparticles. The method is generally applicable to the preparation of AuAu, AuPd, and AuPt core–shell nanostructures with typical porous shells. Moreover, the AuAu isomeric core–shell nanostructure is reported for the first time. The lower oxidation states of AuI, PdII, and PtII are supposed to contribute to the formation of porous core–shell nanostructures instead of yolk-shell nanostructures. The electrocatalytic ethanol oxidation and oxygen reduction reaction (ORR) performance of porous AuPd core–shell nanostructures are assessed as a typical example for the investigation of the advantages of the obtained core–shell nanostructures. As expected, the AuPd core–shell nanostructure indeed exhibits a significantly reduced overpotential (the peak potential is shifted in the positive direction by 44 mV and 32 mV), a much improved CO tolerance (If/Ib is 3.6 and 1.63 times higher), and an enhanced catalytic stability in comparison with Pd nanoparticles and Pt/C catalysts. Thus, porous AuM (M=Au, Pd, and Pt) core–shell nanostructures may provide many opportunities in the fields of organic catalysis, direct alcohol fuel cells, surface-enhanced Raman scattering, and so forth.
Co-reporter:Chengxin Feng, Shaozhen Wang and Baoyou Geng
Nanoscale 2011 vol. 3(Issue 9) pp:3695-3699
Publication Date(Web):25 Jul 2011
DOI:10.1039/C1NR10460H
In this paper, we successfully fabricate Ti(IV) doped WO3 nanocuboids with controlled Ti(IV) contents through a facile, mild, aqueous-phase route. The characterizations clearly exhibit the optimum amount of the Ti(IV) dopant in under these conditions. The obtained photocatalyst shows excellent visible-light-driven photocatalytic performance. It can decompose an organic dye within 70 min under visible-light irradiation. Such a large activity enhancement probably arises from the change of band structure. The results provide an efficient route for the design of photocatalysts with improved visible-light-driven photocatalytic activity as well as a promising material for use in solar cells, nanodevices, and other applications.
Co-reporter:Xuelian Li, Wenjing Wei, Shaozhen Wang, Long Kuai and Baoyou Geng
Nanoscale 2011 vol. 3(Issue 2) pp:718-724
Publication Date(Web):12 Nov 2010
DOI:10.1039/C0NR00617C
In this paper, single-crystalline α-Fe2O3 oblique nanoparallelepipeds are fabricated in high yield via a facile surfactant-free hydrothermal method, which involves oriented aggregation and Ostwald ripening. The obtained nanocrystals have exposed facets of {012}, {01–4} and {−210} with a rhombohedral α-Fe2O3 structure. The gas sensors based on the as-synthesized α-Fe2O3 nanostructures exhibit high sensitivity, short recovery time, and good reproducibility in ethanol and acetone. The superiority of the gas-sensing properties of the obtained nanostructures should be attributed to the surface structure of the nanocrystals. The as-prepared α-Fe2O3 nanocrystals are significant for exploiting their other applications in the future.
Co-reporter:Long Kuai, Shaozhen Wang and Baoyou Geng
Chemical Communications 2011 vol. 47(Issue 21) pp:6093-6095
Publication Date(Web):26 Apr 2011
DOI:10.1039/C0CC05429A
In this communication, we prepare a Au–Pt yolk–shell structure through a galvanic displacement strategy and explore its electrocatalytic properties for methanol oxidation. It exhibits high electrocatalytic activity with notable CO-tolerance.
Co-reporter:Han Jiang, Baoyou Geng, Long Kuai and Shaozhen Wang
Chemical Communications 2011 vol. 47(Issue 8) pp:2447-2449
Publication Date(Web):20 Dec 2010
DOI:10.1039/C0CC04390G
In this communication, a simultaneous reduction–etching route is exploited to fabricate Pt/ZnSnO3 hollow polyhedra. The hollow ZnSnO3 polyhedron is found to act as a novel and efficient support of Pt-based catalyst for methanol electrooxidation in alkaline media.
Co-reporter:Qian Wang, Baoyou Geng, Bo Tao
Journal of Power Sources 2011 Volume 196(Issue 1) pp:191-195
Publication Date(Web):1 January 2011
DOI:10.1016/j.jpowsour.2010.06.035
The fascinating heterostructure of carbon nanotube-supported metal nanoparticles continues to attract interest for developing electrocatalysts for energy sciences. Here, we report the fabrication of noble metal nanocubes carbon nanotube nanocomposites through an electroless deposition route. The as-synthesized carbon nanotubes-supported Pt nanocubes with high active and selective {1 0 0} surfaces display excellent electrocatalytic activities towards the oxygen reduction reaction, which can/will replace current/state of the art cathode catalysts in fuel cells, and thereby improve the catalytic performance and utilization efficiency. The methodology presented here could be further extended to fabricate other one-dimensional materials/noble metal nanostructures.
Co-reporter:Zhoujing Xing, Baoyou Geng, Xuelian Li, Han Jiang, Chengxin Feng and Ting Ge
CrystEngComm 2011 vol. 13(Issue 6) pp:2137-2142
Publication Date(Web):17 Jan 2011
DOI:10.1039/C0CE00741B
Self-assembly 3D porous ZnO nanostrip clusters are prepared through a calcinating hydroxide zinc carbonate precursor route. The fabrication of the precursor involves oriented attachment and self-assembly processes. The obtained porous 3D ZnO architectures show obvious structure enhanced photocatalytic performance, which can be attributed to the special structural feature of an open and porous surface layer that significantly facilitates the diffusion and mass transportation of organic molecules and oxygen species during the photochemical reaction.
Co-reporter:Baoyou Geng, Jun Liu, Yanyan Zhao and Chunhua Wang
CrystEngComm 2011 vol. 13(Issue 2) pp:697-701
Publication Date(Web):04 Oct 2010
DOI:10.1039/C0CE00372G
Homogeneous core–shell structured cuprous oxide (Cu2O) is fabricated through a facile reduction reaction at room temperature (20–25 °C). Ostwald ripening processes are proposed to explain the growth mechanism of the homogeneous Cu2O core–shell structure. The electrochemical impedance spectrum (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) show that the modified electrodes with the obtained homogeneous core–shell Cu2O exhibit high efficiency and convenience toward the detection of dopamine (DA). The anodic peak current increases linearly with the concentration of dopamine in the range of 3.0 × 10−7 to 5 × 10−4 M. The detection limit has been estimated to be 1.0 × 10−7 M. The high sensitivity of the determination of dopamine by using the modified electrode implies that homogeneous core–shell Cu2O may be of great potential in the field of biosensors.
Co-reporter:Shaozhen Wang, Jiahui You, Baoyou Geng and Zhiguo Cheng
CrystEngComm 2011 vol. 13(Issue 2) pp:668-673
Publication Date(Web):30 Sep 2010
DOI:10.1039/C003631E
Hexagonal prisms with pyramid end of cubic ZnSe microstructures are successfully fabricated by a simple chemical vapour deposition method. The obtained ZnSe pyramids grow along the <111> crystal axis and possess sharp tips. Two kinds of ZnSe structures can be obtained through controlling the experimental conditions. The growth mechanism of the product is proposed. The cubic structure of ZnSe and the experimental conditions may lead to the growth of the hexagonal prism with pyramid end. A stable blue emission of 465 nm at room temperature is observed in this novel pyramid-shaped ZnSe material and can be ascribed to the band emission of the cubic phase.
Co-reporter:Long Kuai;Dr. Baoyou Geng;Dr. Shaozhen Wang;Yanyan Zhao;Yinchan Luo ;Han Jiang
Chemistry - A European Journal 2011 Volume 17( Issue 12) pp:3482-3489
Publication Date(Web):
DOI:10.1002/chem.201002949
Abstract
Much effort has gone into generating polyhedral noble metal nanostructures because of their superior electrocatalytic activities for fuel cells. Herein, we report uniform, high-yield icosahedral silver and gold nanoparticles by using a facile one-pot, seedless, water-based approach that incorporates polyvinyl pyrrolidone and ammonia. Electrocatalysis of the oxygen-reduction reaction was carried out in alkaline media to evaluate the performance of the icosahedral nanoparticles. They showed excellent stability and much higher electrocatalytic activity than the spherelike nanoparticles; they display a positive shift in reduction peak potential for O2 of 0.14 and 0.05 V, while the reduction peak currents of the silver and gold icosahedra are 1.5- and 1.6-fold, respectively, better than the spherelike nanoparticles. More importantly, the icosahedral nanoparticles display electrocatalytic activities comparable with commercial Pt/C electrocatalysts. The facile preparation of icosahedral silver and gold nanoparticles and their superior performance in the oxygen reduction reaction render them attractive replacements for Pt as cathode electrocatalysts in alkaline fuel cells.
Co-reporter:Yan Sang, Baoyou Geng and Jie Yang
Nanoscale 2010 vol. 2(Issue 10) pp:2109-2113
Publication Date(Web):03 Aug 2010
DOI:10.1039/C0NR00151A
In this paper, we report on the fabrication of a novel rutile TiO2 architecture consisting of nanorods with {110} exposed facets through a simple hydrothermal method without using any templates. An outside-in ripening mechanism is proposed to account for the formation of the TiO2 architectures.
The formation of the TiO2 architectures can be attributed to the Ostwald step rule and highly acidic medium. Significantly, the current method is suitable for high-yield (>98%) production of the TiO2 architectures with nearly 100% morphological yield. This research provides a facile route to fabricate rutile TiO2 with three-dimensional microstructures based on nanounits. It is easy to realize their industrial-scale synthesis and application because of the simple synthesis method, low cost, and high yield.
Co-reporter:Qian Wang, Baoyou Geng, Shaozhen Wang, Yixing Ye and Bo Tao
Chemical Communications 2010 vol. 46(Issue 11) pp:1899-1901
Publication Date(Web):13 Jan 2010
DOI:10.1039/B922134D
In this paper, we successfully synthesize Fe(OH)3 nanotubes involving the Kirkendall effect. Depending on the calcination conditions, both haematite and magnetite nanotubes are produced. This approach also provides a new synthetic alternative to nanotubes of nonlamellar-structured materials. The as-synthesized magnetite nanotubes have an application as a magnetic resonance imaging contrast agent.
Co-reporter:Zhiguo Cheng, Shaozhen Wang, Qian Wang and Baoyou Geng
CrystEngComm 2010 vol. 12(Issue 1) pp:144-149
Publication Date(Web):30 Sep 2009
DOI:10.1039/B914902C
Ball-flower shaped CuS structures have been synthesized by using mixed copper chloride and thiourea in a simple hydrothermal process employing poly(vinylpyrrolidone) (PVP) as the surfactant. The morphological investigations by field emission scanning electron microscope (FE-SEM) reveal that the ball-flower shaped nanostructures are monodispersed in large quantities. The ball-flower shaped morphologies are strongly dependent on the different ratios of copper chloride to thiourea, the reaction temperature and reaction time. The possible growth mechanism of the formation of ball-flower shaped CuS products is discussed in detail. In addition, the photocatalytic activity of ball-flower shaped CuS architectures has been tested by the degradation of rhodamine B (RhB) under UV light irradiation, showing that the as-prepared ball-flower shaped CuS structures exhibit high photocatalytic activity for the degradation of RhB.
Co-reporter:Dajie Si, Baoyou Geng and Shaozhen Wang
CrystEngComm 2010 vol. 12(Issue 10) pp:2722-2727
Publication Date(Web):22 Mar 2010
DOI:10.1039/B921613H
Several shapes of Eu2+ doped strontium aluminate have been simply obtained by hydrolysis of Sr2+ and Al3+ in hydrothermal and solvothermal systems under mild conditions. The influence of reaction conditions on the formation of the samples has been considered. Flower-like nanoparticles are synthesized in glycol, when the solvent is substituted by H2O, and/or adding NaOH or stirring for 30 min before injecting the prepared Eu(NO3)3, needle cluster-like, sheet-like and lantern-like structures are synthesized. At the same time, the doped Eu3+ is reduced to Eu2+ at much lower temperature, and the emission peaks result from the transition of 4f65d–4f7 of Eu2+ around 405 nm, 435 nm and 530 nm are also observed, no typical peak of Eu3+ is found, which indicates the complete reduction from Eu3+ to Eu2+. The results of this article may give a guide to synthesize the similar Eu2+ doped luminescent materials.
Co-reporter:Caihong Fang, Shaozhen Wang, Qian Wang, Jun Liu, Baoyou Geng
Materials Chemistry and Physics 2010 Volume 122(Issue 1) pp:30-34
Publication Date(Web):1 July 2010
DOI:10.1016/j.matchemphys.2010.03.005
In this paper, we report a solvothermal route to fabricate coralloid hierarchical SnO2 nanostructures. We obtain the product with different surface morphology at different reaction temperature. The breadth and length of the shot rod on the surface change with the temperature. A possible growth mechanism governing the formation of the nanostructures is discussed. Gas sensors based on the as-prepared SnO2 nanostructures exhibit high sensitivity, short recovery time, good reproducibility and linear dependence relation to benzaldehyde/acetone, which is significant for exploiting gas-sensing materials in the future.
Co-reporter:Long Kuai, Baoyou Geng, Xiaoting Chen, Yanyan Zhao, and Yinchan Luo
Langmuir 2010 Volume 26(Issue 24) pp:18723-18727
Publication Date(Web):November 29, 2010
DOI:10.1021/la104022g
In this paper, we successfully fabricate a stable and highly efficient direct sunlight plasmonic photocatalyst Ag−AgBr through a facile hydrothermal and subsequently sunlight-induced route. The diffuse reflectance spectra of Ag−AgBr indicate strong absorption in both UV and visible light region. The obtained photocatalyst shows excellent sunlight-driven photocatalytic performance. It can decompose organic dye within several minutes under direct sunlight irradiation and maintain a high level even though used five times. In addition, both the scanning electron microscopy images and X-ray photoelectron spectroscopy dates reveal the as-prepared photocatalyst to be very stable. Moreover, the mechanism suggests that the high photocatalytic activity and excellent stability result from the super sensitivity of AgBr to light, the surface plasmon resonance of Ag nanoparticles in the region of visible light, and the complexation between Ag+ and nitrogen atom. Thus, the facile preparation and super performance of Ag−AgBr will make it available to utilize sunlight efficiently to remove organic pollutants, destroy bacteria, and so forth.
Co-reporter:Baoyou Geng, Jun Liu, Chunhua Wang
Sensors and Actuators B: Chemical 2010 150(2) pp: 742-748
Publication Date(Web):
DOI:10.1016/j.snb.2010.08.008
Co-reporter:Caihong Fang, Baoyou Geng, Jun Liu and Fangming Zhan
Chemical Communications 2009 (Issue 17) pp:2350-2352
Publication Date(Web):09 Mar 2009
DOI:10.1039/B821459J
Novel ultra-thin ZnSnO3nanowire architectures are prepared through a molecule template route; the products show a strong structure-induced enhancement of photocatalytic performance.
Co-reporter:Qian Wang, Baoyou Geng, Shaozhen Wang, Jun Liu, Zhiguo Cheng and Dajie Si
CrystEngComm 2009 vol. 11(Issue 7) pp:1317-1322
Publication Date(Web):10 Mar 2009
DOI:10.1039/B900997C
This article presents the fabrication of shape-controllable crystalline nickel hydrazine complex structures via a simple sonochemical route. The morphologies of the nickel complex particles are self-organized into hexagonal plate-like and disk-like morphologies depending on the reaction conditions. A possible evolution mechanism of the nickel complex particles with different morphologies is discussed. On the basis of our experimental observations and understandings of the crystal growth, the formation of the plates is believed to mainly attribute to the oriented attachment of small particles. Nickel complex particles can continue self-assemble into impeller or clew-like morphologies on the base of the formed plate-like particles. This work provides a simply, high-yield, and mild reaction conditions route to the nickel complex structures, which might represent a promising method for the preparation of other metal complex structures or inorganic complex structures with desired morphologies.
Co-reporter:Jun Liu, Baoyou Geng, and Shaozhen Wang
Crystal Growth & Design 2009 Volume 9(Issue 10) pp:4384
Publication Date(Web):September 2, 2009
DOI:10.1021/cg9003643
Novel rough ZnS/slick hopeite heterostructured hemispheres are fabricated through a facile hydrothermal route. By controlling the reaction conditions, pure ZnS microspheres, Zn3(PO4)2·4H2O panels and concave heterostructured microspheres also can be obtained. According to experimental results, the equilibrium controlled growth mechanism is proposed for the formation of products. The as-synthesized Zn3(PO4)2·4H2O panels have one Zn-terminated surface and one PO4 tetrahedral group terminated surface. The ZnS nanostructures form on the Zn-terminated surface, resulting in different heterostructures. The obtained ZnS/Zn3(PO4)2·4H2O heterostructured hemispheres show strongly structure-induced enhancement of photocatalytic performance for the photodegradation of Rhodamine B. The superiority of photocatalytic performance is attributed to the high specific surface area, larger size and the heterostructured architectures. This work not only gives insight into understanding the heterostructured growth behavior of microstructures in a solution-phase synthetic system, which may extend to synthesizing other controllable morphology and heterostructured materials but also provides an efficient route to optimize some properties of semiconductors.
Co-reporter:Shaozhen Wang, Qian Wang, Jun Liu, Zhiguo Cheng, Dajie Si and Baoyou Geng
CrystEngComm 2009 vol. 11(Issue 11) pp:2510-2515
Publication Date(Web):07 Aug 2009
DOI:10.1039/B907979N
In this paper, we fabricated crystalline FePO4 microstructures with controlled morphologies at relatively low temperature through kinetic manipulation. The morphology evolution was directly observed during the experiments. The morphologies were mainly determined by the amount of the H3PO4 in the reaction system. The morphologies of the obtained FePO4 changed from rugby to porous microsphere through controlling the concentration of the H3PO4. During the growth of the final porous microspheres, we observed some interesting processes which revealed the special configuration of FePO4 micro/nanostructures. The rational growth mechanism of the FePO4 microstructures was discussed in detail, which was significant not only for researching the properties of iron(III) phosphate, but was also important to understand the kinetic process of crystal growth and guide the synthesis of other crystalline materials.
Co-reporter:Fangming Zhan, Baoyou Geng, Yijun Guo, Lei Wang
Journal of Alloys and Compounds 2009 Volume 482(1–2) pp:L1-L5
Publication Date(Web):12 August 2009
DOI:10.1016/j.jallcom.2009.03.155
Novel NiS architectures were prepared by a facile aqueous solution route with the assistance of diacetyldioxime for the first time. The synthesized products were characterized by X-ray diffraction and scanning electron microscopy. The NiS architectures are in carnation-like morphologies with diameters of 500–800 nm and composed of numerous well-aligned nanosheets of about 20 nm in thickness. It is found that the morphology of the final products is strongly dependent on the experimental parameters, such as the concentration of aqueous NaOH solution and the reaction temperature. Various controlled synthetic experiments indicate that the growth process of NiS architectures can be proposed as occurring by “dissolution” of the ellipsoid-like precursors.
Co-reporter:Baoyou Geng, Jinzhu Ma, Fangming Zhan
Materials Chemistry and Physics 2009 Volume 113(2–3) pp:534-538
Publication Date(Web):15 February 2009
DOI:10.1016/j.matchemphys.2008.08.006
ZnS:Cu2+ nanorods were synthesized through a solution phase thermal decomposition molecule precursor route. The absorption spectra showed a minor red shift with increasing Cu doping concentration. Photoluminescence showed red shift and the intensity of defect luminescence emission would be enhanced as the concentration of Cu ions (0.2–0.4%) increased. The optical properties of the products can be controlled easily by changing Cu doping concentration. This synthetic strategy might exploit a favourable route to synthesize metal-doped semiconductor nanostructures, which are potentially important for optoelectonic nanodevices.
Co-reporter:Jun Liu, Shaozhen Wang, Qian Wang, Baoyou Geng
Sensors and Actuators B: Chemical 2009 Volume 143(Issue 1) pp:253-260
Publication Date(Web):4 December 2009
DOI:10.1016/j.snb.2009.09.027
Co-reporter:Fangming Zhan, Dr. ;Yijun Guo
Chemistry - A European Journal 2009 Volume 15( Issue 25) pp:6169-6174
Publication Date(Web):
DOI:10.1002/chem.200802561
Co-reporter:Baoyou Geng, Fangming Zhan, Han Jiang, Yijun Guo and Zhoujing Xing
Chemical Communications 2008 (Issue 44) pp:5773-5775
Publication Date(Web):01 Oct 2008
DOI:10.1039/B813071J
Single-crystalline Fe3O4nanotubes have been synthesized successfully by using egg albumin as a nanoreactor; these three-dimensional material nanotubes are formed through a rolling mechanism under mild biological conditions.
Co-reporter:B. Y. Geng, J. Z. Ma and J. H. You
Crystal Growth & Design 2008 Volume 8(Issue 5) pp:1443
Publication Date(Web):March 19, 2008
DOI:10.1021/cg700931u
In the present paper, we report on the controllable preparation of single-crystalline Fe3O4 microrhombic dodecahedra possessing the active basal facets in high yield through a facile hydrothermal route. The growth mechanism of the microcrystals is discussed. From a crystallographic point of view, the shapes of the crystals are determined by the ratio of the growth rate along <100> to <111> directions. The pH values of the precursor solution strongly affected the morphologies of the products. When pH value was adjusted to 8–10, well-defined Fe3O4 truncated microrhombic dodecahedra exposing the active basal surfaces ({110}) with narrow size-distribution (<10%) were obtained. The sizes of the Fe3O4 truncated microrhombic dodecahedra are dependent upon the reaction time. The magnetic properties of the products are sensitive to the crystal size. The synthesized well-defined Fe3O4 microcrystals with active basal facets may have important applications in many fields.
Co-reporter:Baoyou Geng, Fangming Zhan, Han Jiang, Zhoujing Xing and Caihong Fang
Crystal Growth & Design 2008 Volume 8(Issue 10) pp:3497-3500
Publication Date(Web):August 28, 2008
DOI:10.1021/cg8002367
In this paper, we report a simple and novel coordination compound precursor route to synthesize the hierarchical dumbbell-like CoOOH nanostructures in high yield. A possible growth mechanism governing the formation of such nanostructures is discussed. The CO-gas-sensing properties of the as-synthesized nanostructures are investigated in detail. The dumbbell-like CoOOH nanostructures have a large active surface area of {110} facets, which can provide sufficient space for the interaction between CoOOH and the detected gases. As a result, the as-prepared dumbbell-like CoOOH nanostructures exhibit a superior sensitivity to CO at room temperature, as well as good reproducibility and short response/recovery times. The as-prepared CoOOH nanostructures could have potential applications in nanosensors.
Co-reporter:Baoyou Geng, Jiahui You, Fangming Zhan, Mingguang Kong and Caihong Fang
The Journal of Physical Chemistry C 2008 Volume 112(Issue 30) pp:11301-11306
Publication Date(Web):July 2, 2008
DOI:10.1021/jp803562a
Hollow ZnSe microspheres were successfully synthesized by a simple chemistry vapor deposition method in a horizontal tube furnace. The as-obtained samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry. The growth mechanism of the ZnSe microspheres was discussed in detail, which can be addressed as the SO 2 gas trap, expand, and burst during the deposition process. The morphology evolutions of the microspheres were observed. The size, open mouth, surface state, and morphology of the hollow ZnSe microspheres could be adjusted through changing the experimental conditions. Photoluminescence measurements show that the as-synthesized hollow ZnSe microspheres exhibit strong blue emissions with the intensities being adjustable. These hollow ZnSe microspheres may have promising applications in blue emitters, gas sensors, microreactors, and catalyst carriers.
Co-reporter:Yijun Guo, Baoyou Geng, Li Zhang, Fangming Zhan and Jiahui You
The Journal of Physical Chemistry C 2008 Volume 112(Issue 51) pp:20307-20311
Publication Date(Web):2017-2-22
DOI:10.1021/jp8081497
In this paper, multilayer superstructures of single-crystalline ZnTe nanowire films have been prepared through a new growth process: well-aligned ZnTe nanowires congregate into nanowire film. The growth process takes place discontinuously and consequently produces many layers of aligned ZnTe nanowire superstructures. These interesting findings are apparently different from the conventional vapor−liquid− solid (VLS) process but following a new multiple nucleation growth model. The intriguing growth mode of multilayer superstructures of aligned ZnTe nanowires may enrich our understanding of the growth mechanism of nanowires. The photoluminescence spectrum of the obtained multilayer ZnTe NWs superstructures exhibits strong free exciton emission peak and relatively weak Ia line, indicating that the layers are of high quality, which may have potential applications in nanodevices.
Co-reporter:Baoyou Geng, Xiaowang Liu, Jinzhu Ma, Qingbo Du
Materials Science and Engineering: B 2007 Volume 145(1–3) pp:17-22
Publication Date(Web):20 December 2007
DOI:10.1016/j.mseb.2007.09.065
Metal (Cd, Cu, and Ni) sulfide nanocrystals have been synthesized by a single-source molecular precursor method. The size of the nanocrystals can be well controlled by adjusting the ration of the oleylamine and precursors. This synthesis may represent a general approach towards metal sulfide nanocrystals, which may promise both adequate academic and practical interest in the development of synthetic methodologies for inorganic nanocrystals, and in the expansion of their potential applications.
Co-reporter:Jun Liu, Shaozhen Wang, Qian Wang, Baoyou Geng
Sensors and Actuators B: Chemical (4 December 2009) Volume 143(Issue 1) pp:253-260
Publication Date(Web):4 December 2009
DOI:10.1016/j.snb.2009.09.027
Novel self-assembled quasi-spherical cuprous oxide (Cu2O) microarchitectures with rough surface are produced by a facile microwave chemical route without any template or surfactant. The reaction temperature and concentration of Cu2+ play important roles to the morphology of the final products. For explaining the growth process, a possible “nucleate-ripen-split-self-assemble” mechanism is proposed. The gas-sensing properties of the as-synthesized self-assembled Cu2O microstructures are investigated in detail. The results indicate that the quasi-spherical Cu2O microstructures exhibit superior response to ethanol vapor and H2S, as well as short response/recovery times and good reproducibility.
Co-reporter:Yixing Ye, Long Kuai and Baoyou Geng
Journal of Materials Chemistry A 2012 - vol. 22(Issue 36) pp:NaN19138-19138
Publication Date(Web):2012/08/02
DOI:10.1039/C2JM33893A
This paper reported a facile template-free route to prepare hierarchical Fe3O4–Co3O4 yolk–shell nanostructures. These highly porous architectures, with a diameter of about 2 μm, were assembled from Co3O4 flower-like shells and Fe3O4 sphere core. A series of experiments with different conditions were carried out to determine the key factors in this typical solvothermal synthesis that led to the formation of the obtained yolk–shell nanostructures, and a possible growth mechanism was proposed. Sequentially, some other similar metal oxide nanostructures were also obtained in this way. Importantly, the obtained Fe3O4–Co3O4 yolk–shell nanostructures exhibit excellent electrocatalytic ORR performance. The half-wave potential of the yolk–shell nanostructures is about 5 and 80 mV positive-shifted compared to that of the independent Co3O4 and Fe3O4 nanoparticles. The current density of O2 reduction for the Fe3O4–Co3O4 yolk–shell nanostructures is also much higher than that of Co3O4 and Fe3O4 nanoparticles. The enhanced electrocatalytic performance for Fe3O4–Co3O4 yolk–shell nanostructures may make them available to be an efficient and cheap noble-metal free cathodic catalyst for PEMFCs.
Co-reporter:Zhengcui Wu, Huan Wang, Yejing Xue, Baoer Li and Baoyou Geng
Journal of Materials Chemistry A 2014 - vol. 2(Issue 41) pp:NaN17510-17510
Publication Date(Web):2014/08/15
DOI:10.1039/C4TA02989E
The surface modification of semiconductors is an important strategy for tuning solar-driven photocatalytic activity. Herein, ZnO nanorods/ZnSe heteronanostructure arrays with a tunable microstructure of the ZnSe shell, with a high visible light photocatalytic activity, are produced by liquid chemical conversion using ZnO nanorods arrays on a zinc foil. By varying the ammonia concentration, the secondary ZnSe shell can be formed of nanoparticles, nanorods and nanosheets, engineered by the oriented attachment of small ZnSe nanoparticles. By virtue of the synergistic advantages of the enhanced visible light adsorption capability and the effective separation of electron–hole pairs obtained by coupling ZnO nanorods with ZnSe nanostructures, the ZnO nanorods/ZnSe heteronanostructure arrays exhibit high visible light driven photocatalytic activities as well as shell microstructure dependent photocatalytic performances.
Co-reporter:Baoyou Geng, Fangming Zhan, Han Jiang, Yijun Guo and Zhoujing Xing
Chemical Communications 2008(Issue 44) pp:NaN5775-5775
Publication Date(Web):2008/10/01
DOI:10.1039/B813071J
Single-crystalline Fe3O4nanotubes have been synthesized successfully by using egg albumin as a nanoreactor; these three-dimensional material nanotubes are formed through a rolling mechanism under mild biological conditions.
Co-reporter:Yanyan Zhao, Long Kuai and Baoyou Geng
Catalysis Science & Technology (2011-Present) 2012 - vol. 2(Issue 6) pp:NaN1274-1274
Publication Date(Web):2012/03/20
DOI:10.1039/C2CY20074K
Visible light-driven photocatalysts have attracted a great deal of attention for their direct use of solar energy. In this paper, an efficient and low-cost visible light-driven composite photocatalyst, comprising of Ag–AgBr/γ-Al2O3 nanostructures, has been facilely prepared by a surfactant-controlled precipitation–deposition and subsequent light-driven route. Hollow flower-like γ-Al2O3 nanostructures was chosen as the support. CTAB controlled the size of the deposited nanoparticles in both the Br source and the surfactant. The microstructures, surface chemical composition, visible light-driven photocatalytic performance and mechanism have been investigated systematically by SEM, TEM, XPS and so forth. The Ag–AgBr nanoparticles were distributed uniformly on the surface of the hollow flower-like γ-Al2O3 nanostructures, whose specific surface area value reached 116.5 m2 g−1. The Ag–AgBr/γ-Al2O3 composite nanostructures exhibit photocatalytic advantages over pure Ag–AgBr nanoparticles, such as decomposing aromatic compounds and organic dyes within several minutes of visible light irradiation. They also have good stabilities meaning the photocatalytic activity seldom decreases even when used 5 times under visible light irradiation. Meanwhile, the amount of Ag–AgBr needed and the cost decreases significantly. Thus, the as-prepared composite photocatalyst, consisting of Ag–AgBr/γ-Al2O3 nanostructures, will be an efficient and low-cost material for the removal of organic pollutants under visible light irradiation.
Co-reporter:Haoran Du, Chao Yuan, Kuangfu Huang, Wenhai Wang, Kai Zhang and Baoyou Geng
Journal of Materials Chemistry A 2017 - vol. 5(Issue 11) pp:NaN5350-5350
Publication Date(Web):2017/02/10
DOI:10.1039/C6TA10327H
A mesoporous bowknot-like Co3O4 material has been synthesized through a facile hydrothermal method, using cobalt nitrate as the cobalt source, urea as the precipitator and gelatin as the guide agent, followed by calcination at 600 °C in air. Morphology characterization reveals that this bowknot-like Co3O4 material possesses a mesoporous structure consisting of nanoparticles. Electrochemical experiments illustrate that the mesoporous bowknot-like Co3O4 anode material exhibits a superior first and 100th reversible specific capacity of 1427.9 mA h g−1 and 1388.8 mA h g−1 at 0.2C, respectively. This material also delivers a high charge capacity of 751.3 mA h g−1 after 150 cycles at 2C. The novel preparation method and satisfactory performance make the bowknot-like Co3O4 a good candidate as a high-performance anode material for use in Lithium-Ion Batteries (LIBs).
Co-reporter:Long Kuai, Shaozhen Wang and Baoyou Geng
Chemical Communications 2011 - vol. 47(Issue 21) pp:NaN6095-6095
Publication Date(Web):2011/04/26
DOI:10.1039/C0CC05429A
In this communication, we prepare a Au–Pt yolk–shell structure through a galvanic displacement strategy and explore its electrocatalytic properties for methanol oxidation. It exhibits high electrocatalytic activity with notable CO-tolerance.
Co-reporter:Qian Wang, Baoyou Geng, Shaozhen Wang, Yixing Ye and Bo Tao
Chemical Communications 2010 - vol. 46(Issue 11) pp:NaN1901-1901
Publication Date(Web):2010/01/13
DOI:10.1039/B922134D
In this paper, we successfully synthesize Fe(OH)3 nanotubes involving the Kirkendall effect. Depending on the calcination conditions, both haematite and magnetite nanotubes are produced. This approach also provides a new synthetic alternative to nanotubes of nonlamellar-structured materials. The as-synthesized magnetite nanotubes have an application as a magnetic resonance imaging contrast agent.
Co-reporter:Caihong Fang, Baoyou Geng, Jun Liu and Fangming Zhan
Chemical Communications 2009(Issue 17) pp:NaN2352-2352
Publication Date(Web):2009/03/09
DOI:10.1039/B821459J
Novel ultra-thin ZnSnO3nanowire architectures are prepared through a molecule template route; the products show a strong structure-induced enhancement of photocatalytic performance.
Co-reporter:Han Jiang, Baoyou Geng, Long Kuai and Shaozhen Wang
Chemical Communications 2011 - vol. 47(Issue 8) pp:NaN2449-2449
Publication Date(Web):2010/12/20
DOI:10.1039/C0CC04390G
In this communication, a simultaneous reduction–etching route is exploited to fabricate Pt/ZnSnO3 hollow polyhedra. The hollow ZnSnO3 polyhedron is found to act as a novel and efficient support of Pt-based catalyst for methanol electrooxidation in alkaline media.
Co-reporter:Wenzheng Li, Long Kuai, Qing Qin and Baoyou Geng
Journal of Materials Chemistry A 2013 - vol. 1(Issue 24) pp:NaN7117-7117
Publication Date(Web):2013/04/03
DOI:10.1039/C3TA00106G
In this work, Ag–Au bimetallic nanostructures with various component ratios were successfully synthesized through a simple kinetic controlled co-reduction route at room temperature. The structure and composition of the as-obtained products has been adjusted and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDX) elemental mapping, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and UV-visible spectra. Meanwhile, Ag67.3Au32.7 bimetallic nanostructures were identified to show the best sensing performance in the enzyme-free detection of H2O2 with a short response time (<5 s) at an applied potential of −0.5 V, a linear range from 0.01 to 68 mM (R2 = 0.998) with a lower detection limit of 0.2 μM and higher sensitivity of 600 μA mM−1 cm−2. More importantly, the component-dependent electrochemical sensor data of different component nanostructures has been studied, and the synergistic effect between Ag and Au can lead to the best performance of H2O2 sensing. The interaction of diffusion and adsorption we raised reasonably has been used to explain the component-depended performance. Significantly, this work supplies an understanding of the bimetallic component effect for H2O2 sensing by the control of the components of the Ag–Au bimetal, and find out the Ag67.3Au32.7 bimetallic nanostructures are the most excellent candidate for enzyme-free H2O2 sensing.
