Co-reporter:Xiao-Ning Ren, Zhi-Yi Hu, Jun Jin, Liang Wu, Chao Wang, Jing Liu, Fu Liu, Min Wu, Yu Li, Gustaaf Van Tendeloo, and Bao-Lian Su
ACS Applied Materials & Interfaces September 6, 2017 Volume 9(Issue 35) pp:29687-29687
Publication Date(Web):August 16, 2017
DOI:10.1021/acsami.7b07226
Phase-junctions between a cocatalyst and its semiconductor host are quite effective to enhance the photocatalytic activity and are widely studied, while reports on the phase-juncted cocatalyst are still rare. In this work, we report the deposition of the Pt/PtO phase-juncted nanodots as cocatalyst via NaOH modification of an interconnected meso-macroporous TiO2 network with high surface area and inner-particle mesopores to enhance the performance of photocatalytic H2 production. Our results show that NaOH modification can largely influence Pt/PtO phase-juncted nanodot formation and dispersity. Compared to the TiO2 nanoparticles, the hierarchically meso-macroporous TiO2 network containing 0.18 wt % Pt/PtO phase-juncted cocatalyst demonstrates a highest photocatalytic H2 rate of 13 mmol g–1 h–1 under simulated solar light, and possesses a stable cycling activity without obvious decrease after five cycles. Such high H2 production performance can be attributed to both the phase-juncted Pt/PtO providing more active sites while PtO suppresses the undesirable hydrogen back reaction, and the special hierarchically porous TiO2 network with inner-particle mesopores presenting short diffusion path lengths for photogenerated electrons and enhanced light harvesting efficiency. This work suggests that Pt/PtO phase-juncted cocatalyst on hierarchically porous TiO2 nanostructures is a promising strategy for advanced photocatalytic H2 production.Keywords: biomolecular self-assembly; cocatalyst; hierarchically meso-macroporous TiO2; photocatalytic H2 production; Pt/PtO phase-junction nanodots;
Co-reporter:Ming-Hui Sun, Shao-Zhuan Huang, Li-Hua Chen, Yu Li, Xiao-Yu Yang, Zhong-Yong Yuan and Bao-Lian Su
Chemical Society Reviews 2016 vol. 45(Issue 12) pp:3479-3563
Publication Date(Web):03 Jun 2016
DOI:10.1039/C6CS00135A
Over the last decade, significant effort has been devoted to the applications of hierarchically structured porous materials owing to their outstanding properties such as high surface area, excellent accessibility to active sites, and enhanced mass transport and diffusion. The hierarchy of porosity, structural, morphological and component levels in these materials is key for their high performance in all kinds of applications. The introduction of hierarchical porosity into materials has led to a significant improvement in the performance of materials. Herein, recent progress in the applications of hierarchically structured porous materials from energy conversion and storage, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine is reviewed. Their potential future applications are also highlighted. We particularly dwell on the relationship between hierarchically porous structures and properties, with examples of each type of hierarchically structured porous material according to its chemical composition and physical characteristics. The present review aims to open up a new avenue to guide the readers to quickly obtain in-depth knowledge of applications of hierarchically porous materials and to have a good idea about selecting and designing suitable hierarchically porous materials for a specific application. In addition to focusing on the applications of hierarchically porous materials, this comprehensive review could stimulate researchers to synthesize new advanced hierarchically porous solids.
Co-reporter:Hai-Bo Huang, Yue Yang, Li-Hua Chen, Yun Wang, Shao-Zhuan Huang, Jia-Wei Tao, Xiao-Ting Ma, Tawfique Hasan, Yu Li, Yan Xu and Bao-Lian Su
Nanoscale 2016 vol. 8(Issue 21) pp:10928-10937
Publication Date(Web):27 Jan 2016
DOI:10.1039/C5NR09149G
Engineering hierarchical structures of electrode materials is a powerful strategy for optimizing the electrochemical performance of an anode material for lithium-ion batteries (LIBs). Herein, we report the fabrication of hierarchical TiO2/C nanocomposite monoliths by mediated mineralization and carbonization using bacterial cellulose (BC) as a scaffolding template as well as a carbon source. TiO2/C has a robust scaffolding architecture, a mesopore–macropore network and TiO2–C heterostructure. TiO2/C-500, obtained by calcination at 500 °C in nitrogen, contains an anatase TiO2–C heterostructure with a specific surface area of 66.5 m2 g−1. When evaluated as an anode material at 0.5 C, TiO2/C-500 exhibits a high and reversible lithium storage capacity of 188 mA h g−1, an excellent initial capacity of 283 mA h g−1, a long cycle life with a 94% coulombic efficiency preserved after 200 cycles, and a very low charge transfer resistance. The superior electrochemical performance of TiO2/C-500 is attributed to the synergistic effect of high electrical conductivity, anatase TiO2–C heterostructure, mesopore–macropore network and robust scaffolding architecture. The current material strategy affords a general approach for the design of complex inorganic nanocomposites with structural stability, and tunable and interconnected hierarchical porosity that may lead to the next generation of electrochemical supercapacitors with high energy efficiency and superior power density.
Co-reporter:Shao-Zhuan Huang, Yi Cai, Jun Jin, Jing Liu, Yu Li, Hong-En Wang, Li-Hua Chen, Tawfique Hasan and Bao-Lian Su
Journal of Materials Chemistry A 2016 vol. 4(Issue 11) pp:4264-4272
Publication Date(Web):16 Feb 2016
DOI:10.1039/C6TA00594B
Unique walnut-shaped porous MnO2/carbon nanospheres (P-MO/C-NSs) with high monodispersity have been designed and prepared for lithium storage via in situ carbonization of amorphous MnO2 nanospheres. Polyvinylpyrrolidone (PVP) is utilized as both the surfactant for morphology control and carbon source for carbon scaffold formation accompanied with MnO2 crystallization. Such a unique walnut-shaped porous nanostructure with an intimate carbon layer provides a large contact area with the electrolyte, short transport path length for Li+, low resistance for charge transfer and superior structural stability. The P-MO/C-NS electrode demonstrates high lithium storage capacity (1176 mA h g−1 at 100 mA g−1), very good cycling stability (100% capacity retention versus the second cycle) and excellent rate capability (540 mA h g−1 at 1000 mA g−1). We propose that it is the deep oxidation of Mn2+ to Mn3+ in P-MO/C-NSs, which results in an extraordinarily high capacity of 1192 mA h g−1 at a current density of 1000 mA g−1 after a long period of cycling, very close to the maximum theoretical reversible capacity of MnO2 (1230 mA h g−1). This is the highest value ever observed for MnO2-based electrodes at such a rate. The high lithium storage capacity and rate capability can be attributed to the enhanced reaction kinetics owing to the walnut-shaped porous nanostructure with an intimate carbon layer. This work provides a meaningful demonstration of designing porous nanostructures of carbon-coated metal oxides undergoing deep conversion reactions for enhanced electrochemical performances.
Co-reporter:Min Yan, Yang Zhang, Yu Li, Yongqi Huo, Yong Yu, Chao Wang, Jun Jin, Lihua Chen, Tawfique Hasan, Binjie Wang and Bao-Lian Su
Journal of Materials Chemistry A 2016 vol. 4(Issue 24) pp:9403-9412
Publication Date(Web):16 May 2016
DOI:10.1039/C6TA03211G
Lithium–sulfur (Li–S) batteries are receiving significant attention as an alternative power system for advanced electronic devices because of their high theoretical capacity and energy density. In this work, we have designed manganese dioxide (MnO2) nanosheet functionalized sulfur@poly(3,4-ethylenedioxythiophene) core–shell nanospheres (S@PEDOT/MnO2) for high performance lithium–sulfur (Li–S) batteries. A PEDOT layer is used to address the low electrical conductivity of sulfur and acts as a protective layer to prevent dissolution of polysulfides. The MnO2 nanosheets functionalized on PEDOT further provide a high active contact area to enhance the wettability of the electrode materials with electrolytes and further interlink the polymer chains to improve the conductivity and stability of the composite. As a result, S@PEDOT/MnO2 exhibits an improved capacity of 827 mA h g−1 after 200 cycles at 0.2C (1C = 1673 mA g−1) and a further ∼50% enhancement compared to S@PEDOT (551 mA h g−1) without MnO2 functionalization. In particular, the discharge capacity of S@PEDOT/MnO2 is 545 mA h g−1 after 200 cycles at 0.5C. Our demonstration here indicates that the functionalization of inorganic nanostructures on conducting polymer coated sulfur nanoparticles is an effective strategy to improve the electrochemical cycling performance and stability of sulfur cathodes for Li–S batteries.
Co-reporter:Jun Jin, Xiao-Ning Ren, Yi Lu, Xian-Feng Zheng, Hong-En Wang, Li-Hua Chen, Xiao-Yu Yang, Yu Li and Bao-Lian Su
RSC Advances 2016 vol. 6(Issue 74) pp:70485-70492
Publication Date(Web):18 Jul 2016
DOI:10.1039/C6RA14895F
Hierarchically porous TiO2/carbon hollow spheres (TiO2/C-HS) have been designed and prepared through a facile one-pot template-free hydrothermal route using sucrose as a carbon source, TiO2 solid spheres as a TiO2 source and NH4F as a structure-directing reagent. The nanocrystal constructed hierarchically porous hollow spherical structure offers enough space for electrolyte penetration and storage and a short path length for Li+ diffusion and e− transport. The carbon layer on TiO2 surface improves its conductivity as well as the structure stability. As a result, such a special hollow structure with carbon layers exhibits enhanced lithium storage properties comparing with the solid spheres. The TiO2/C-HS anode exhibits discharge capacities of 286, 235, 197, 164 and 127 mA h g−1 at various rates of 0.2, 0.5, 1, 2 and 5C (1C = 168 mA g−1), respectively. A capacity of 175 mA h g−1 still remains after 200 cycles at 1C, demonstrating a very high lithium insertion coefficient of 0.52, a little higher than the theoretical value of 0.5. SEM, TEM, HRTEM and electrochemical impedance spectra (EIS) techniques have been utilized to understand the Li+ insertion process and structural stability. Our results reveal that the high electrochemical performance of the TiO2/C-HS anode can be attributed to the synergy of the hierarchically porous hollow structure, carbon layer and newly formed numerous ∼5 nm Li2Ti2O4 on the surface of the TiO2 nanocrystals.
Co-reporter:Xiao-Ning Ren, Liang Wu, Jun Jin, Jing Liu, Zhi-Yi Hu, Yu Li, Tawfique Hasan, Xiao-Yu Yang, Gustaaf Van Tendeloo and Bao-Lian Su
RSC Advances 2016 vol. 6(Issue 32) pp:26856-26862
Publication Date(Web):07 Mar 2016
DOI:10.1039/C6RA00332J
Biomolecular self-assembly is an effective synthesis strategy for material fabrication with unique structural complexity and properties. For the first time, we integrate inner-particle mesoporosity in a three-dimensional (3D) interconnected macroporous TiO2 structure via the mediation of biomolecular self-assembly of the lipids and proteins from rape pollen coats and Pluronic P123 to optimize the structure for high performance lithium storage. Benefitting from the hierarchically 3D interconnected macro-mesoporous structure with high surface area, small nanocrystallites and good electrolyte permeation, such a unique porous structure demonstrates superior electrochemical performance, with high initial coulombic efficiency (94.4% at 1C) and a reversible discharge capacity of 161, 145, 127 and 97 mA h g−1 at 2, 5, 10 and 20C for 1000 cycles, with 79.3%, 89.9%, 90.1% and 87.4% capacity retention, respectively. Using SEM, TEM and HRTEM observations on the TiO2 materials before and after cycling, we verify that the inner-particle mesoporosity and the Li2Ti2O4 nanocrystallites formed during the cycling process in interconnected macroporous structure greatly enhance the cycle life and rate performance. Our demonstration here offers opportunities towards developing and optimizing hierarchically porous structures for energy storage applications via biomolecular self-assembly.
Co-reporter:Xianfeng Zheng, Hongen Wang, Chao Wang, Zhao Deng, Lihua Chen, Yu Li, Tawfique Hasan, Bao-Lian Su
Nano Energy 2016 Volume 22() pp:269-277
Publication Date(Web):April 2016
DOI:10.1016/j.nanoen.2016.02.017
•High-performance supercapacitor-like Li-ion battery concept has been proposed.•3 nm NiO nanodots have been deposited on macroporous nickel foam by self-assembly method.•Binder-free three-dimensional (3D) hierarchically macro-mesoporous electrodes have been prepared.•This electrode architecture simultaneously enables rapid ion transfer and ultra-short solid-phase ion diffusion.•The electrode exhibits supercapacitor-like high rate capabilities with high lithium battery capacities.We report a binder-free three-dimensional (3D) macro-mesoporous electrode architecture via self-assembly of 3 nm NiO nanodots on macroporous nickel foam for high performance supercapacitor-like lithium battery. This electrode architecture provides a hierarchically 3D macro-mesoporous electrolyte-filled network that simultaneously enables rapid ion transfer and ultra-short solid-phase ion diffusion. Benefitting from the structural superiority owing to the interconnected porous hierarchy, the electrode exhibits supercapacitor-like high rate capabilities with high lithium battery capacities during the discharge-charge process: a very high capacity of 518 mA h g−1 at an ultrahigh current density of 50 A g−1. It exceeds at least ~10 times than that of the state-of-the-art graphite anode, which shows only ~50 mA h g−1 at ~2 to 3 A g−1 as anode for Li-ion batteries. The preparation method of 3D interconnected hierarchically macro-mesoporous electrode presented here can provide an efficient new binder-free electrode technique towards the development of high-performance supercapacitor-like Li-ion batteries.A binder-free 3D interconnected macro-mesoporous NiO electrode for rapid ion transfer and ultra-short solid-phase ion diffusion has been developed via self-assembly of 3 nm NiO nanodots on macroporous nickel foam. The electrode enables Li-ion storage battery working with supercapacitor rate capability while maintaining high battery capacity. This work described here highlights a new approach to fabricate high-performance electrochemical energy storage devices with both high power as well as energy density.
Co-reporter:Nan Jiang, Xiao-Yu Yang, Guo-Liang Ying, Ling Shen, Jing Liu, Wei Geng, Ling-Jun Dai, Shao-Yin Liu, Jian Cao, Ge Tian, Tao-Lei Sun, Shi-Pu Li and Bao-Lian Su
Chemical Science 2015 vol. 6(Issue 1) pp:486-491
Publication Date(Web):17 Oct 2014
DOI:10.1039/C4SC02638A
Self-repair is nature's way of protecting living organisms. However, most single cells are inherently less capable of self-repairing, which greatly limits their wide applications. Here, we present a self-assembly approach to create a nanoshell around the cell surface using nanoporous biohybrid aggregates. The biohybrid shells present self-repairing behaviour, resulting in high activity and extended viability of the encapsulated cells (eukaryotic and prokaryotic cells) in harsh micro-environments, such as under UV radiation, natural toxin invasion, high-light radiation and abrupt pH-value changes. Furthermore, an interaction mechanism is proposed and studied, which is successful to guide design and synthesis of self-repairing biohybrid shells using different bioactive molecules.
Co-reporter:Meryam Zalfani, Benoit van der Schueren, Zhi-Yi Hu, Joanna C. Rooke, Ramzi Bourguiga, Min Wu, Yu Li, Gustaaf Van Tendeloo and Bao-Lian Su
Journal of Materials Chemistry A 2015 vol. 3(Issue 42) pp:21244-21256
Publication Date(Web):08 Sep 2015
DOI:10.1039/C5TA00783F
Novel 3DOM BiVO4/TiO2 nanocomposites with intimate contact were for the first time synthesized by a hydrothermal method in order to elucidate their visible-light-driven photocatalytic performances. BiVO4 nanoparticles and 3DOM TiO2 inverse opal were fabricated respectively. These materials were characterized by XRD, XPS, SEM, TEM, N2 adsorption–desorption and UV-vis diffuse (UV-vis) and photoluminescence spectroscopies. As references for comparison, a physical mixture of BiVO4 nanoparticles and 3DOM TiO2 inverse opal powder (0.08:1), and a BiVO4/P25 TiO2 (0.08:1) nanocomposite made also by the hydrothermal method were prepared. The photocatalytic performance of all the prepared materials was evaluated by the degradation of rhodamine B (RhB) as a model pollutant molecule under visible light irradiation. The highly ordered 3D macroporous inverse opal structure can provide more active surface areas and increased mass transfer because of its highly accessible 3D porosity. The results show that 3DOM BiVO4/TiO2 nanocomposites possess a highly prolonged lifetime and increased separation of visible light generated charges and extraordinarily high photocatalytic activity. Owing to the intimate contact between BiVO4 and large surface area 3DOM TiO2, the photogenerated high energy charges can be easily transferred from BiVO4 to the 3DOM TiO2 support. BiVO4 nanoparticles in the 3DOM TiO2 inverse opal structure act thus as a sensitizer to absorb visible light and to transfer efficiently high energy electrons to TiO2 to ensure long lifetime of the photogenerated charges and keep them well separated, owing to the direct bandgap of BiVO4 of 2.4 eV, favourably positioned band edges, very low recombination rate of electron–hole pairs and stability when coupled with photocatalysts, explaining the extraordinarily high photocatalytic performance of 3DOM BiVO4/TiO2 nanocomposites. It is found that larger the amount of BiVO4 in the nanocomposite, longer the duration of photogenerated charge separation and higher the photocatalytic activity. This work can shed light on the development of novel visible light responsive nanomaterials for efficient solar energy utilisation by the intimate combination of an inorganic light sensitizing nanoparticle with an inverse opal structure with high diffusion efficiency and high accessible surface area.
Co-reporter:Jun Jin, Shao-Zhuan Huang, Yu Li, He Tian, Hong-En Wang, Yong Yu, Li-Hua Chen, Tawfique Hasan and Bao-Lian Su
Nanoscale 2015 vol. 7(Issue 30) pp:12979-12989
Publication Date(Web):26 Jun 2015
DOI:10.1039/C5NR02800K
A hierarchical nanosheet-constructed yolk–shell TiO2 (NYTiO2) porous microsphere is synthesized through a well-designed, one-pot, template-free solvothermal alcoholysis process using tetraethylenepentamine (TEPA) as the structure directing reagent. Such a yolk–shell structure with a highly porous shell and dense mesoporous core is quite advantageous as an anode material for lithium ion batteries (LIBs). The outer, 2D nanosheet-based porous (15 nm) shell and the nanocrystal-based inner mesoporous (3 nm) core provide a stable, porous framework, effective grain boundaries and a short diffusion pathway for Li+ and electron transport, facilitating lithium insertion/extraction. The voids between the core and the shell can not only store the electrolyte due to capillary and facilitate charge transfer across the electrode/electrolyte interface but also buffer the volume change during the Li+ insertion/extraction. As a result, NYTiO2 demonstrates excellent Li+ capacity with outstanding cycle performance and superior rate capability at different rates for >700 cycles, retaining a 225 mA h g−1 reversible capacity after 100 cycles at 1 C. In particular, the reversible capacity can still be maintained at 113 mA h g−1 after 100 cycles at 10 C. We also observe the formation of homogeneously distributed 5–10 nm Li2Ti2O4 nanocrystallites on the surface of the nanosheets during the discharge–charge process. The synergy of the yolk–shell structure with dual mesopores in the shell and core and the Li2Ti2O4 nanocrystallites endow the hierarchical NYTiO2 with high reversible capacity, excellent rate capability and outstanding cycle performance.
Co-reporter:Jun Jin;Shao-Zhuan Huang;Jing Liu;Yu Li;Li-Hua Chen;Yong Yu;Hong-En Wang;Clare P. Grey
Advanced Science 2015 Volume 2( Issue 7) pp:
Publication Date(Web):
DOI:10.1002/advs.201500070
A hierarchical mesoporous TiO2 nanowire bundles (HM-TiO2-NB) superstructure with amorphous surface and straight nanochannels has been designed and synthesized through a templating method at a low temperature under acidic and wet conditions. The obtained HM-TiO2-NB superstructure demonstrates high reversible capacity, excellent cycling performance, and superior rate capability. Most importantly, a self-improving phenomenon of Li+ insertion capability based on two simultaneous effects, the crystallization of amorphous TiO2 and the formation of Li2Ti2O4 crystalline dots on the surface of TiO2 nanowires, has been clearly revealed through ex situ transmission electron microcopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman, and X-ray photoelectron spectroscopy (XPS) techniques during the Li+ insertion process. When discharged for 100 cycles at 1 C, the HM-TiO2-NB exhibits a reversible capacity of 174 mA h g−1. Even when the current density is increased to 50 C, a very stable and extraordinarily high reversible capacity of 96 mA h g−1 can be delivered after 50 cycles. Compared to the previously reported results, both the lithium storage capacity and rate capability of our pure TiO2 material without any additives are among the highest values reported. The advanced electrochemical performance of these HM-TiO2-NB superstructures is the result of the synergistic effect of hybriding of amorphous and crystalline (anatase/rutile) phases and hierarchically structuring of TiO2 nanowire bundles. Our material could be a very promising anodic material for lithium-ion batteries.
Co-reporter:Hua-Wen Huang, Jing Liu, Guangfu He, Yao Peng, Min Wu, Wei-Hong Zheng, Li-Hua Chen, Yu Li and Bao-Lian Su
RSC Advances 2015 vol. 5(Issue 123) pp:101910-101916
Publication Date(Web):17 Nov 2015
DOI:10.1039/C5RA20508E
Tunable macro–mesoporous ZnO (M/m-ZnO) nanostructures with a wurtzite hexagonal structure have been successfully synthesized using polymer colloids as a hard template and 20–40 nm ZnO nanoparticles as a precursor via controlling the ratios of colloids and ZnO nanoparticles. The as-prepared macro–mesoporous ZnO nanostructures are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Gas sensing performance is carried out for ethanol and acetone at different temperatures and concentrations. The gas sensing results show that the tunable M/m-ZnO nanostructures exhibit excellent gas sensing performances because the hierarchical macro–mesopores provide a large contacting surface area for electrons, oxygen and target gas molecules, offer smooth transport channels for target gas diffusion and finally enhance the gas molecular diffusion kinetics. The M/m-ZnO-600 nm demonstrates the best performance for ethanol and acetone detection. In addition, the sensor based on M/m-ZnO-600 nm gives obvious tendencious selectivity and a good repeatability and long-term stability to acetone at the optimum temperature of 300 °C. This work suggests that the macro–mesoporous ZnO is a potential material for advanced gas sensing.
Co-reporter:Dai-Song Chen, Wen-Bei Yu, Zhao Deng, Jing Liu, Jun Jin, Yu Li, Min Wu, Li-Hua Chen and Bao-Lian Su
RSC Advances 2015 vol. 5(Issue 68) pp:55520-55526
Publication Date(Web):16 Jun 2015
DOI:10.1039/C5RA06083D
Hollow Cu2O microspheres (0.7 to 4 μm in diameter) with two active {111} and {110} facets have been prepared in water/ethylene glycol (H2O/EG) solution via a fast hydrothermal route in only 1 h. Due to the dangling “Cu” atoms in the highly active {111} and {110} facets, the microspheres demonstrate preferential selective adsorption and photodegradation for negatively charged methyl orange (MO), comparing to cationic rhodamine B (RhB) and neutral phenol. The 0.7 μm hollow Cu2O microspheres show the best adsorption capacity and photodegradation performance for MO removal: 49% MO can be adsorbed in 60 min and 99.8% MO can be fully removed under visible light illumination in 80 min, owing to the two active {110} and {111} facets and hollow structure. To exactly evaluate the photocatalytic efficiency, a new methodology is proposed by deducting the adsorption effect. The results show that in spite of 99.2% MO is removed from the solution under visible light illumination in 60 min, 14% MO is still adsorbed on the catalyst, which can be totally removed under further 20 min illumination. Our synthesis strategy presents a new opportunity for the preparation of hollow structures with high active facets. And the proposed accurate evaluation methodology may be extended to other photocatalysts with high adsorption capability for organic pollutants.
Co-reporter:Jun Jin, Shao-Zhuan Huang, Jie Shu, Hong-En Wang, Yu Li, Yong Yu, Li-Hua Chen, Bin-Jie Wang, Bao-Lian Su
Nano Energy 2015 Volume 16() pp:339-349
Publication Date(Web):September 2015
DOI:10.1016/j.nanoen.2015.07.001
•Hierarchical nanorods chains constructed TiO2 hollow microspheres (HNC-TiO2-HMSs) have been designed and prepared.•Innovative synthesis strategy to engineer the formation of HNC-TiO2-HMSs.•Excellent Li+ storage capacity with outstanding cycle performance and superior rate capability.•Self-improving phenomenon of cycle performance and storage capacity.•in-situ XRD study on the Li+ insertion process and the phase transformation.Hierarchical nanorods chains-constructed TiO2 hollow microspheres (HNC-TiO2-HMSs) have been designed and prepared through a facile one-pot fluorine-free solvothermal alcoholysis route using TiCl4 and isopropanol reaction system. Owing to the assembly of radially oriented nanorods chains leading to the formation of the shell of the hollow spheres, a large series of straight channels along nanorods chains are formed. Such highly porous hollow microspheres with hollow cavity, straight nanorods chains and straight nanochannels are highly desirable for Li ions batteries because such structure can easily store the electrolyte, facilitate the charge diffusion and Li+ insertion and buffer the volume change during the Li+ insertion/extraction process. One of the key innovation of the present work is the fine tuning of water amount released from the esterification of alcohol to induce in a well controlled hydrolysis of TiCl4 and engineer precisely HNC-TiO2-HMSs formation. Most importantly, the released Cl− ions direct the nanorods growing along (001) crystal plane and self-assembling along the radial direction accompanying with nanorods size controlling to form HNC-TiO2-HMSs. The obtained TiO2 anode material with such special structure demonstrates excellent Li+ storage capacity with outstanding cycle performance and superior rate capability at different rates over 700 cycles: a reversible capacity of 216 mA h g−1 is obtained after 100 cycles at 1 C and a reversible capacity of 112 mA h g−1 is retained after 100 cycles at 10 C. The SEM, TEM, HRTEM and in-situ XRD techniques have been utilized to shed light on the Li+ insertion process and the phase transformation. Most importantly, a self-improving phenomenon of cycle performance and storage capacity was observed owing to the formation of numerous ~5 nm Li2Ti2O4 nanocrystals formed on the surface of the nanorods chains. The results reveal that the high performance of the as-prepared HNC-TiO2-HMSs in terms of storage capacity, cycle performance and rate capability can be attributed to the synergy of the special structure and the self-improving phenomenon. Our simple reaction system may provide a concrete example on the construction of novel hollow spherical porous anode materials for high performance lithium batteries.
Co-reporter:Shao-Zhuan Huang, Yi Cai, Jun Jin, Jing Liu, Yu Li, Yong Yu, Hong-En Wang, Li-Hua Chen, Bao-Lian Su
Nano Energy 2015 Volume 12() pp:833-844
Publication Date(Web):March 2015
DOI:10.1016/j.nanoen.2015.01.040
•New lamellar manganese alkoxide (Mn-DEG) microspheres were synthesized via solution-phase reaction.•DEG acts as both solvent and structure-directing reagent.•The HM-MO/C-MS are from the in situ carbonization of Mn-DEG.•The HM-MO/C-MS combine various advantages to improve lithium storage.•The HM-MO/C-MS deliver highly enhanced lithium battery performance.•The synthesis strategy can be broadened to other metal oxides/carbon composites.Two types of hierarchical mesoporous urchin-like Mn3O4/carbon microspheres (HM-MO/C-MS) have been prepared via the in situ carbonization of the newly synthesized lamellar manganese alkoxide (Mn-DEG) along with the crystallization of Mn3O4 in air (MO-A) and nitrogen (MO-N), respectively. Such unique HM-MO/C-MS with high surface area provides obvious advantages including a large contact area with electrolyte, a short transport path for Li+ ions, a low resistance for charge transfer, and a superior structural stability. When used as an anode material for lithium ion batteries in the voltage range of 0.01–3 V, the HM-MO/C-MS obtained in nitrogen (MO-N) exhibits high lithium storage capacity (915 mA h g−1 at 100 mA g−1 for 50 cycles), great cycling stability (94.5% capacity retention versus the second cycle) and excellent rate capability (510 mA h g−1 at 1000 mA g−1). In particular, when cycling at a high current density of 1500 mA g−1, the reversible capacity of the MO-N sample can still be maintained as high as 480 mA h g−1 with a high capacity retention of 93.7% after 200 cycles. Even in a narrower voltage range of 0.01–1.5 V, the lithium storage capacity of the MO-N sample can reach 556 mA h g−1 at 100 mA g−1 with a very good cycling stability (over 91% capacity retention from the second cycle) and have an excellent rate capability of 269 mA h g−1 at 1000 mA g−1. Both MO-N and MO-A samples present a very high volumetric capacity of 741.2 mA h cm−3 and 647.4 mA h cm−3 at 100 mA g−1, respectively. Such high performances both in the voltage ranges of 0.01–3 V and 0.01–1.5 V are among the highest reported. Ex-situ SEM images showed clearly the excellent morphological and structural stability of our materials. The results demonstrate that the unique hierarchical mesoporous microspheres/carbon structure is favorable for improving the cyclability and rate capability in energy storage applications. Our effective synthesis strategy can be broadened to construct other mesoporous metal oxides/carbon composites for high-performance lithium ion batteries.
Co-reporter:Shao-Zhuan Huang, Yi Cai, Jun Jin, Yu Li, Xian-Feng Zheng, Hong-En Wang, Min Wu, Li-Hua Chen and Bao-Lian Su
Journal of Materials Chemistry A 2014 vol. 2(Issue 34) pp:14099-14108
Publication Date(Web):25 Jun 2014
DOI:10.1039/C4TA02339K
Low electron transportation and lithium ion diffusion coefficient in laminar vanadium oxide nanostructures limit their electrochemical performance for lithium ion batteries. In this work, V2O5 nanowires and VOx nanotubes were obtained via heat treatment of the pristine vanadium oxide nanotubes at different temperatures under air and nitrogen atmospheres, respectively, and then used as cathode materials for lithium ion batteries. It is interesting to note that the pristine vanadium nanotubes were transformed to V2O5 nanowires under an ambient atmosphere while the nanotube morphology can be maintained under an inert N2 atmosphere. The electrochemical results show that the V2O5 nanowires obtained at 400 °C deliver the best cycling performance with an initial discharge capacity as high as 278 mA h g−1 and the best rate capability with a discharge capacity of 115 mA h g−1 at 500 mA g−1. The VOx nanotubes obtained at 400 °C show the highest lithium storage capacity of 218 mA h g−1 with excellent capability retention and the best rate capability among all the nanotube samples. The improvement of electrochemical properties of V2O5 nanowires and VOx nanotubes can be attributed to the synergy of the enhanced surface area and better crystallinity. The different electrochemical properties reveal the existence of four different modes of Li ion intercalation/de-intercalation behaviors in V2O5 nanowires and VOx nanotubes. It is very interesting to note that the Li ion intercalation/de-intercalation in amorphous VOx nanotubes (VOx + yLi+ + ye− → LiyVOx) can induce a phase transformation from amorphous matrix to layered crystalline structure. This present work reveals that the electrochemical properties, in particular the cycling stability of vanadium oxide nanostructures, can be improved by tuning the one-dimensional structures' crystallinity. Furthermore, the phase transformation from amorphous matrix to layered crystalline structure of VOx nanotubes may open an exciting door for all the amorphous nanostructures for the application of LIBs.
Co-reporter:Jun Jin, Shao-Zhuan Huang, Jing Liu, Yu Li, Dai-Song Chen, Hong-En Wang, Yong Yu, Li-Hua Chen and Bao-Lian Su
Journal of Materials Chemistry A 2014 vol. 2(Issue 25) pp:9699-9708
Publication Date(Web):28 Apr 2014
DOI:10.1039/C4TA01775G
As anode materials for lithium ion batteries, two three dimensionally ordered macroporous TiO2, one with disordered inter-particle mesopores formed by the aggregation of nanoparticles (3DOM) and another with inner-particle mesopores generated by a surfactant templating strategy (3DOMM), have been synthesized using poly(styrene-methyl methacrylate-3-sulfopropyl methacrylate potassium) (P(St-MMA-SPMAP)) spheres as a hard template and their electrochemical properties are compared. SEM and TEM observations reveal that both 3DOM TiO2 and 3DOMM TiO2 have well-ordered macropores and interconnected macropore walls with a regular periodicity. 3DOMM TiO2 demonstrates a specific surface area of 139 m2 g−1, which is higher than that of 3DOM TiO2 (99 m2 g−1) due to the smaller crystallite size and inner-particle mesopores. The electrolyte adsorption results show that both 3DOM TiO2 and 3DOMM TiO2 have similar adsorption capacities despite a difference in the surface area. Electrochemical impendence spectroscopy analysis shows that 3DOMM TiO2 has a lower charge transfer resistance and faster Li+ diffusion coefficient than 3DOM TiO2. Moreover, both 3DOM TiO2 and 3DOMM TiO2 possess excellent initial capacity of 248 mA h g−1 and 235 mA h g−1 at 0.2 C and 208 mA h g−1 and 202 mA h g−1 at 1 C, respectively. The reversibility study demonstrates that the 3DOMM TiO2 displays higher cycling capacity, superior rate behavior and higher Coulombic efficiency because the higher surface area provides more active sites and the presence of the inner-particle mesopores in the walls of macropores serve as a bicontinuous transport path and affords a shorter path length for diffusion of Li ions compared with the 3DOM TiO2 and its crystallite aggregated mesopores. The reversible capacity of 106 mA h g−1 observed for the 3DOMM TiO2 can be retained after 200 charge–discharge cycles at a relatively high current rate of 4 C. This cycle stability performance can be equally attributed to the crystallite size and inner-particle mesopores in the 3DOMM TiO2. Moreover, the existence of a bicontinuous porous structure in the 3DOMM TiO2 can further enhance the lithium insertion/extraction capacity at high rates. We believe that this study can shed light on the 3DOMM structure as a promising material for highly enhanced performance in lithium ion batteries.
Co-reporter:Nan Jiang, Guo-Liang Ying, Shao-Yin Liu, Ling Shen, Jie Hu, Ling-Jun Dai, Xiao-Yu Yang, Ge Tian and Bao-Lian Su
Chemical Communications 2014 vol. 50(Issue 97) pp:15407-15410
Publication Date(Web):17 Oct 2014
DOI:10.1039/C4CC06323F
Amino acid-based biohybrids have been developed to self-assemble on the surface of desulfurizing bacteria to form nanothin and nanoporous shells. The shells not only endow the encapsulated cells with reusability, but also offer platforms to incorporate titania and magnetic nanoparticles to improve the desulfurizing activity and the separation efficiency.
Co-reporter:Chao Wang, Shaozhuan Huang, Li Wang, Zhao Deng, Jun Jin, Jing Liu, Lihua Chen, Xianfeng Zheng, Yu Li and Bao-Lian Su
RSC Advances 2013 vol. 3(Issue 6) pp:1699-1702
Publication Date(Web):04 Dec 2012
DOI:10.1039/C2RA22202G
Hierarchical core–corona porous γ-Al2O3 nanostructures have been synthesized through the reaction of toluene diluted TMA with water by controlling the methane leaching. The obtained γ-Al2O3 core–corona nanostructures exhibit high thermal stability and excellent performance for polluted water treatment.
Co-reporter:Xiao-Yu Yang, Ge Tian, Nan Jiang and Bao-Lian Su
Energy & Environmental Science 2012 vol. 5(Issue 2) pp:5540-5563
Publication Date(Web):05 Dec 2011
DOI:10.1039/C1EE02391H
Biofuel cells provide a versatile means to generate electrical power from environmentally friendly biomass or biofuels. Immobilization technology has played an important role in the design of biofuel cells. This review addresses recent advances in immobilization technology applied to assembling biofuel cells. After identifying the advantages and problems of biofuel cells, the immobilization technology, which offers a sustainable and effective solution for biofuel cell design, is thoroughly presented: (i) A brief introduction to immobilization methods, including adsorption, covalent binding and entrapment, is first presented. (ii) The immobilization structure and nanostructures are emphasized, which strongly influence mass and electron transfer, including zero, one, two, and three dimensional nanostructures are then discussed. (iii) The immobilization materials, which are considered as a critical factor in immobilization technology, including polymer, carbon, oxide and metallic nanomaterials, sol–gel based materials and particularly composite materials, are reviewed to conclude. The interesting issues related to the future of biofuel cell design are also highlighted, for example, the 3D electrode assembly using low dimensional structures as a future challenge, biofuel cells within logic systems as a new aspect, crystalline mesoporous carbon with high enzyme loading as a future desired material, and composite materials with multiple functions and structures as a hot area of work.
Co-reporter:Yu Li;Zheng-Yi Fu
Advanced Functional Materials 2012 Volume 22( Issue 22) pp:4634-4667
Publication Date(Web):
DOI:10.1002/adfm.201200591
Abstract
Materials with hierarchical porosity and structures have been heavily involved in newly developed energy storage and conversion systems. Because of meticulous design and ingenious hierarchical structuration of porosities through the mimicking of natural systems, hierarchically structured porous materials can provide large surface areas for reaction, interfacial transport, or dispersion of active sites at different length scales of pores and shorten diffusion paths or reduce diffusion effect. By the incorporation of macroporosity in materials, light harvesting can be enhanced, showing the importance of macrochannels in light related systems such as photocatalysis and photovoltaics. A state-of-the-art review of the applications of hierarchically structured porous materials in energy conversion and storage is presented. Their involvement in energy conversion such as in photosynthesis, photocatalytic H2 production, photocatalysis, or in dye sensitized solar cells (DSSCs) and fuel cells (FCs) is discussed. Energy storage technologies such as Li-ions batteries, supercapacitors, hydrogen storage, and solar thermal storage developed based on hierarchically porous materials are then discussed. The links between the hierarchically porous structures and their performances in energy conversion and storage presented can promote the design of the novel structures with advanced properties.
Co-reporter:Li-Hua Chen, Shu-Tao Xu, Xiao-Yun Li, Ge Tian, Yu Li, Joanna Claire Rooke, Guang-Shan Zhu, Shi-Lun Qiu, Ying-Xu Wei, Xiao-Yu Yang, Zhong-Min Liu, Bao-Lian Su
Journal of Colloid and Interface Science 2012 Volume 377(Issue 1) pp:368-374
Publication Date(Web):1 July 2012
DOI:10.1016/j.jcis.2012.03.018
Hierarchical porous architecture with interconnected trimodal micro-meso-macroporous systems constructed from uniform zeolite Zr-doped silicalite-1 nanocrystals has been prepared. The synthesis has been made by using glycerin as a reaction medium via a quasi-solid-state crystallization of hierarchically meso-macroporous zirconosilicate precursor under the effect of the structure directing agent TPAOH. The presence of glycerin is crucial in the synthesis systems to maintain the porous hierarchy. The pores inter-connectivity, Zr location in the framework, the acidity and the catalytic activity have been studied by laser-hyperpolarized 129Xe NMR spectroscopy, UV–visible spectroscopy, temperature-programmed desorption of ammonia and the catalytic isopropylbenzene cracking probe reaction, respectively. The products possess well-defined macrochannels interconnected with mesopores located in the macropore walls, which in turn have been constructed from microporous MFI-type zeolite units. 129Xe NMR study indicated that the hierarchically micro-, meso-, macro-pore systems are homogeneously distributed throughout the final materials and well interconnected, which is important for molecular diffusion. The TPD-NH3 investigation revealed that the hierarchically micro-meso-macroporous materials constructed from zeolite Zr-Silicalite-1 nanocrystals present strong acidity.Graphical abstractHighlights► Hierarchical porous material with interconnected trimodal micro-meso-macroporous structure. ► Zr-doped silicalite-1 nanocrystals. ► A quasi-solid-state crystallization process. ► A good interconnectivity of micro-meso-macropores system. ► The product MMM-ZrS-1 presents strong acidity.
Co-reporter:Alexandre Léonard, Philippe Dandoy, Emeric Danloy, Grégory Leroux, Christophe F. Meunier, Joanna C. Rooke and Bao-Lian Su
Chemical Society Reviews 2011 vol. 40(Issue 2) pp:860-885
Publication Date(Web):07 Jan 2011
DOI:10.1039/C0CS00024H
This critical review highlights the advances that have been made over recent years in the domain of whole-cell immobilisation and encapsulation for applications relating to the environment and human health, particularly focusing on examples of photosynthetic plant cells, bacteria and algae as well as animal cells. Evidence that encapsulated photosynthetic cells remain active in terms of CO2 sequestration and biotransformation (solar driven conversion of CO2 into biofuels, drugs, fine chemicals etc.), coupled with the most recent advances made in the field of cell therapy, reveals the need to develop novel devices based on the preservation of living cells within abiotic porous frameworks. This review shall corroborate this statement by selecting precise examples that unambiguously demonstrate the necessity and the benefits of such smart materials. As will be described, the handling and exploitation of photosynthetic cells are enhanced by entrapment or encapsulation since the cells are physically separated from the liquid medium, thereby facilitating the recovery of the metabolites produced. In the case of animal cells, their encapsulation within a matrix is essential in order to create a physical barrier that can protect the cells auto-immune defenders upon implantation into a living body. For these two research axes, the key parameters that have to be kept in mind when designing hybrid materials will be identified, concentrating on essential aspects such as biocompatibility, mechanical strength and controlled porosity (264 references).
Co-reporter:Joanna Claire Rooke, Alexandre Léonard, Hugo Sarmento, Christophe F. Meunier, Jean-Pierre Descy and Bao-Lian Su
Journal of Materials Chemistry A 2011 vol. 21(Issue 4) pp:951-959
Publication Date(Web):11 Nov 2010
DOI:10.1039/C0JM02712J
A photosynthetic bioreactor for CO2 assimilation has been designed using silica sol–gel immobilisation technologies with the chlorophyta Botryococcus braunii (Kützing) and Chlorella vulgaris (Beijerinck). The living hybrid gels formed revealed a mesoporosity that enabled diffusion of nutrients and gases, promoting the light and dark photosynthetic reactions from within the bulk of the material. To determine the efficiency of the photosynthetic bioreactor in terms of CO2 remediation, the activity and viability of the encapsulated cells have been monitored through oximetry, 14C assimilation, pulse amplitude modulation fluorimetry and confocal microscopy, revealing a long term productivity of living hybrid materials capable of photosynthetic processes for at least 80 days. Structural and textural properties of the gels were established through 29Si MASNMR and N2 physisorption respectively.
Co-reporter:Xiao-Yu Yang, Alexandre Léonard, Arnaud Lemaire, Ge Tian and Bao-Lian Su
Chemical Communications 2011 vol. 47(Issue 10) pp:2763-2786
Publication Date(Web):18 Jan 2011
DOI:10.1039/C0CC03734F
In this paper, we will thoroughly review a novel and versatile self-formation phenomenon that can be exploited to target porous hierarchies of materials without need of any external templates only on the basis of the chemistry of metal alkoxides and alkylmetals. These hierarchically porous materials have unique structures, which are made of either parallel funnel-like/straight macrochannels or 3D continuous interconnected macroporous foams with micro/mesoporous walls. The self-generated porogen mechanism has been proposed, leading to a series of techniques to tailor porous hierarchy, i.e. the use of different chemical precursors (single metal alkoxides, mixed metal alkoxides, single molecular precursors with two different alkoxide functionalities, alkylmetals, etc., …), the control of their hydrolysis and condensation rates (pH, chelating agents,…) and the addition of alkoxysilanes as co-reactant. Various chemical compositions from single or binary metal oxides, to aluminosilicates, aluminophosphates, silicoaluminophosphates, metallophosphates,… can be prepared, offering a panel of potential applications. Some perspectives have been proposed to transform the synthesized materials with a hierarchy of pore sizes to micro–meso–macroporous crystalline materials with zeolite architectures. The advantages of this self-formation preparation method have been discussed compared to traditional templating methods. The possibility to combine with other strategies, for example soft or hard templating, to target even more sophisticated hierarchically meso–macroporous materials with specific structure and function for various applications has been presented. The “hierarchical catalysis” concept has been re-visited.
Co-reporter:Bao-Lian Su, Nicolas Moniotte, Noan Nivarlet, Li-Hua Chen, Zheng-Yi Fu, Jonathan Desmet, Jing Li
Journal of Colloid and Interface Science 2011 Volume 358(Issue 1) pp:136-145
Publication Date(Web):1 June 2011
DOI:10.1016/j.jcis.2011.02.050
Highly sensitive and selective nanosensor for labile iron pool (LIP) determination, has been designed and prepared by immobilization of Fluoresceine–Desferrioxamine (Fl–DFO), a bifunctional fluoro-siderophore probe molecule with great affinity for iron ions (pKf = 30.7), into highly ordered mesoporous silica structure. Different immobilization methods of Fl–DFO molecules, such as their encapsulation in surfactant micelles used as templating agents for the synthesis of mesoporous silica, direct impregnation into the mesochannels of as-synthesized mesoporous silica and their surface anchoring by covalent binding with propylamine groups implanted by post-synthesis on the internal surface of mesochannels, have been explored. Each nanohybrid has been fully characterized by small angle XRD, TEM, SEM, solid state 29Si and 13C MAS NMR and N2 adsorption–desorption. The fluorescence properties of nanohybrids obtained have been correlated with the immobilization methods, generating interesting information concerning the localization of Fl–DFO molecules in the channels of mesoporous silica. The leaching of Fl–DFO molecules from mesoporous materials has been investigated. The nanosensor prepared by surface anchoring of Fl–DFO at the internal surface of mesochannels showed high performances with no leaching effect and high sensitivity in regards to its responses to ferric ions. Its fluorescence intensity decreased as soon as first FeIII ions are in contact with this nanosensor. A linear relationship between the fluorescence intensity and the ferric ions concentration was observed in low micromolar range. The selectivity of this nanosensor towards other metal ions has also been tested and shown its high affinity to ferric ions. This study can allow the design of a stable, portable, simple, regenerable and cost-effective nanosensor highly sensitive and selective for iron ions with detection limits in the range of cellular LIP in cells, e.g. lower micromolar range.Graphical abstractHighly sensitive and selective nanosensor for labil iron pool (LIP) determination has been designed and prepared by immobilization of Fluoresceine–Desferrioxamine (Fl–DFO) into highly ordered mesoporous silica.Research highlights► Highly selective and sensitive nanosensor. ► Fl–DFO/highly ordered mesoporous silica. ► Fl–DFO surface anchoring by covalent binding. ► Fl–DFO molecule location on the fluorescence properties. ► Iron ions dosing.
Co-reporter:Zhiguang Guo, Weimin Liu, Bao-Lian Su
Journal of Colloid and Interface Science 2011 Volume 353(Issue 2) pp:335-355
Publication Date(Web):15 January 2011
DOI:10.1016/j.jcis.2010.08.047
Nature is the creation of aesthetic functional systems, in which many natural materials have vagarious structures. Inspired from nature, such as lotus leaf, butterfly’ wings, showing excellent superhydrophobicity, scientists have recently fabricated a lot of biomimetic superhydrophobic surfaces by virtue of various smart and easy routes. Whilst, many examples, such as lotus effect, clearly tell us that biomimicry is dissimilar to a simple copying or duplicating of biological structures. In this feature article, we review the recent studies in both natural superhydrophobic surfaces and biomimetic superhydrophobic surfaces, and highlight some of the recent advances in the last four years, including the various smart routes to construct rough surfaces, and a lot of chemical modifications which lead to superhydrophobicity. We also review their functions and applications to date. Finally, the promising routes from biomimetic superhydrophobic surfaces in the next are proposed.Graphical abstractInspired from nature, such as lotus leaf, showing excellent superhydrophobicity, a lot of biomimetic superhydrophobic surfaces were recently fabricated by means of various smart and easy routes, such as wet chemical reaction, self-assembly, electrospinning. At the same time, many examples, such as lotus effect, clearly tell us that biomimicry is dissimilar to a simple copying or duplicating of biological structures. This review highlighted some of the recent advances in recent years, especially in last four years, on superhydrophobic surfaces, from natural to biomimetic surfaces and their functions. We also proposed the promising routes from biomimetic superhydrophobic surfaces in the further.Research highlights► The state of the art on superhydrophobic surfaces. ► Lessons from nature to biomimetic surfaces. ► From multiple functions to applications. ► Future direction on biomimetic superhydrophobic surfaces. ► Work as nature, do as nature and produce as nature.
Co-reporter:Bao-Lian Su, Xu-Chu Ma, Fen Xu, Li-Hua Chen, Zheng-Yi Fu, Nicolas Moniotte, Sami Ben Maamar, Roger Lamartine, Francis Vocanson
Journal of Colloid and Interface Science 2011 Volume 360(Issue 1) pp:86-92
Publication Date(Web):1 August 2011
DOI:10.1016/j.jcis.2011.03.084
A layer of macrocyclic calix[4]arene derivatives has been grafted on the internal surface of the mesochannels of the ordered mesoporous SBA-15 to develop highly efficient trap for heavy transition metal (HTM) ions. To ensure the successful anchoring of calix[4]arene derivatives on the surface of SBA-15, two different types of calix[4]arene derivatives, one with one trimethoxysilane functional group and another with two trimethoxysilane functional groups have been explored. XRD, N2 adsorption and TEM results provide strong evidence that the mesoporous structure of the supporting materials retain their long range ordering throughout the grafting process. Solid-state NMR, TG and FT-IR spectroscopy indicate that both types of calix[4]arene derivatives can be well-anchored on the surface of the wall of SBA-15. Calix[4]arene derivative with only one trimethoxysilane functional group showed high grafting efficiency compared to that with two trimethoxysilane functional groups due to the intramolecular and intermolecular polycondensation between two trimethoxysilane functional groups. The HTM ions extraction capacity in aqueous solution of macrocycle functionalized SBA-15 nanohybrides for a series of HTM ions has been studied. The obtained materials demonstrated very high HTM ions extraction capacity up to 96% for Pb2+ in aqueous solution.Graphical abstractMacrocyclic calix[4]arene derivatives functionalized mesoporous SBA-15 showed high capacity for HTM ions extraction from aqueous solution and the present work can open a new exciting avenue for the preparation of new nanomaterials with integrated organic functional groups and advanced performances.Highlights► Macrocyclic calix[4]arene derivatives functionalized mesoporous SBA-15. ► HTM ions extraction in aqueous solution. ► Environmental application.
Co-reporter:Arnaud Lemaire, Bao-Lian Su
Microporous and Mesoporous Materials 2011 Volume 142(Issue 1) pp:70-81
Publication Date(Web):June 2011
DOI:10.1016/j.micromeso.2010.11.019
The effect of tetraethoxysilane (TEOS), tetrapropoxysilane (TPOS), tetrabutoxysilane (TBOS) and a mixture of tetramethoxysilane (TMOS) and TEOS as silicon co-reactant on the formation of hierarchically structured meso-macroporous aluminosilicates and the tetrahedral aluminium content in the framework using a single molecular alkoxide precursor, (sec-BuO)2–Al–O–Si(OEt)3, has been intensively investigated. The use of alkoxysilane as a co-reactant and highly alkaline media improves the heterocondensation rates between the highly reactive aluminium-alkoxide part of the single molecular precursor and the added alkoxysilanes, and minimizes the cleavage of the intrinsic Al–O–Si linkage. The very unique hierarchical meso-macroporosity was auto-generated by the hydrodynamic flow of solvents released during the rapid hydrolysis and condensation processes of this double alkoxide and the inorganic silica co-reactant. No external structural agent was required to template these porous structures. The particles obtained featured outstanding macrostructure with regular micrometer-sized macrovoids and displaying 3D interconnections. Importantly, the diameter of the micrometer-sized macrovoids found in the final materials and the thickness of the mesoporous walls separating these voids can be tuned by adjusting the reactivity of alkoxysilanes used as co-reactant. Higher reactivity of alkoxysilanes can improve the tetrahedral aluminium content in the meso-macroporous framework and reduce the cleavage of Al–O–Si linkage of the single molecular precursor. These correlations are of primary importance for targeting advanced materials with well defined meso- and macroporosities and tetrahedral aluminium content.Graphical abstractHighly spongy hierarchical structured meso-macroporous aluminosilicates with high tetrahedral aluminium content and 3D interconnectivity have been synthesized from a single-source molecular precursor (sec-BuO)2–Al–O–Si(OEt)3 and tetraalkylsilanes as silicon co-reactant.Research highlights► Hierarchically structured meso-macroporous aluminosilicates displaying 3D interconnections and high tetrahedral Al content. ► Single molecular alkoxide precursor, (sec-BuO)2–Al–O–Si(OEt)3. ► The effect of tetraalkylsilanes (TEOS, TPOS, TBOS and TMOS + TEOS) as silicon co-reactant on the formation. ► Tuning the diameter of the micrometer-sized macrovoids and the thickness of the mesoporous walls by adjusting the reactivity of alkoxysilanes.
Co-reporter:Arnaud Lemaire, Joanna Claire Rooke, Li-Hua Chen, and Bao-Lian Su
Langmuir 2011 Volume 27(Issue 6) pp:3030-3043
Publication Date(Web):January 28, 2011
DOI:10.1021/la104679h
Hierarchically structured spongy meso−macroporous aluminosilicates with high tetrahedral aluminum content were synthesized from a mixture of single molecular alkoxide precursor, (sec-BuO)2−Al−O−Si(OEt)3, already containing Si−O−Al bonds, and a silica coreactant, tetramethoxysilane (TMOS). The spontaneous byproduct templated macroporous structure formation has been directly visualized using in situ high-resolution optical microscopy (OM), allowing the crucial observation of a microbubble dispersion which is directly correlated to the macrostructure observed by electronic microscopies (SEM and TEM). This discovery leads to a comparative study with meso−macroporous pure metal oxide and to a proposal of the formation mechanism of meso−macroporous aluminosilicates with 3D interconnectivity. The aluminosilicate phase/microbubbles emulsion is produced by a phase separation process occurring between the aluminosilicate nanoparticles and the liquid hydrolysis−condensation reaction byproducts (water, methanol, ethanol, and butanol). The use of alkoxysilane improves the heterocondensation rates between the highly reactive aluminum alkoxide part of the single precursor and added silica species but, above all, leads to the spontaneous generation of an unusual meso−macroporosity in alkaline media. The particles obtained at pH = 13.0 featured regular micrometer-sized macrospheres separated by very thin mesoporous walls and connected by submicrometric openings, providing a 3D interconnectivity. The slight increase in pH value to 13.5 induced significant modifications in morphology and textural properties due to the slower gelification process of the aluminosilicate phase, resulting in the formation of an aluminosilicate material constituted of 1−2 µm large independent hollow mesoporous spheres.
Co-reporter:Dr. Christophe F. Meunier;Dr. Xiao-Yu Yang;Dr. Joanna C. Rooke; Bao-Lian Su
ChemCatChem 2011 Volume 3( Issue 3) pp:476-488
Publication Date(Web):
DOI:10.1002/cctc.201000410
Abstract
Natural photosynthesis is a highly efficient process that uses sunlight irradiation to convert carbon dioxide into value-added biomass. This review summarizes the recent advances in the transformation of solar energy into electrical power through the exploitation of photosynthetically active proteins, organelles, and living cells. During the past decade, the considerable progress made in bioentities immobilization offers the possibility to integrate biological systems into electronic devices. Even though solar energy technologies are gaining increasing attention, photosynthetic biofuel cells are still in their infancy. Advances in materials science are necessary to protect, stabilize, and even increase the catalytic performance of bioentities. Moreover, host materials could guarantee higher loading and better electrical charge transport, which would be crucial in the commercial success of biofuel cells. In the future, such semi-artificial hybrid assemblies could hold promise as sustainable sources of energy.
Co-reporter:Dr. Li-Hua Chen;Xiao-Yun Li;Dr. Ge Tian;Dr. Yu Li;Hai-Yan Tan;Dr. Gustaaf VanTendeloo;Dr. Guang-Shan Zhu;Dr. Shi-Lun Qiu;Dr. Xiao-Yu Yang;Dr. Bao-Lian Su
ChemSusChem 2011 Volume 4( Issue 10) pp:1452-1456
Publication Date(Web):
DOI:10.1002/cssc.201100181
Co-reporter: Bao-Lian Su ; Qingjie Zhang; Davide Bonifazi; Jinlin Li
ChemSusChem 2011 Volume 4( Issue 10) pp:1327-1331
Publication Date(Web):
DOI:10.1002/cssc.201100614
Co-reporter:Dr. Li-Hua Chen;Xiao-Yun Li;Dr. Ge Tian;Dr. Yu Li;Dr. Joanna Claire Rooke; Guang-Shan Zhu; Shi-Lun Qiu;Dr. Xiao-Yu Yang ; Bao-Lian Su
Angewandte Chemie International Edition 2011 Volume 50( Issue 47) pp:11156-11161
Publication Date(Web):
DOI:10.1002/anie.201105678
Co-reporter:Dr. Christophe F. Meunier;Dr. Xiao-Yu Yang;Dr. Joanna C. Rooke; Bao-Lian Su
ChemCatChem 2011 Volume 3( Issue 3) pp:
Publication Date(Web):
DOI:10.1002/cctc.201190009
Co-reporter:Alexandre Léonard , Joanna C. Rooke, Christophe F. Meunier, Hugo Sarmento, Jean-Pierre Descy and Bao-Lian Su
Energy & Environmental Science 2010 vol. 3(Issue 3) pp:370-377
Publication Date(Web):19 Jan 2010
DOI:10.1039/B923859J
With the aim of designing photobioreactors (PBR) based on a smart exploitation of microalgae for the production of biofuels and metabolites of interest, this paper describes a novel approach where cyanobacteria are entrapped within highly porous silica matrices. With this concept, it would be possible to work with a constant population of organisms for a continuous (and increased) photoproduction of metabolites, in contrast to “one-shot” uses of liquid cultures. Different hybrid materials based on porous silica gels are described with a special emphasis on finding the most appropriate immobilisation conditions for prolonged cell survival. It is found that an aqueous route based on acid-exchanged sodium silicate combined with the use of silica nanoparticles as a gel-strengthening species shows the best results with a high primary production rate post immobilisation and a preservation of the photosynthetic pigments of up to 35 weeks. Oxygen production, though very low, could be evidenced up to 17 weeks after entrapment, demonstrating the suitability of using porous silica matrices in PBR design.
Co-reporter:Yu Li, Xiao-Yu Yang, Ge Tian, Aurélien Vantomme, Jiaguo Yu, Gustaaf Van Tendeloo and Bao-Lian Su
Chemistry of Materials 2010 Volume 22(Issue 10) pp:3251
Publication Date(Web):April 27, 2010
DOI:10.1021/cm100491r
A simple and spontaneous one-pot self-formation procedure that is easy to scale up has been developed based on the chemistry of trimethylaluminum (TMA), leading to thermally stable macroporous crystalline alumina with a very unique and unprecedented three-dimensional (3D) hierarchical pore structure consisting of well-defined wormlike mesopores. TMA is the precursor of both product and porogene (viz, two working functions within the same molecule (2 in 1)). The materials obtained have been intensively characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption−desorption, and mercury porosimetry. The open cagelike macrocavities are self-constructed by mesoporous nanorods (diameter of ca. 40−70 nm), which are themselves formed by a random assembly of fibrous nanoparticles 5−6 nm in size. Optical microscopy (OM) has been used in situ to follow the synthesis procedure, which led to the proposal of the formation mechanism. Methane molecules as porogens, which were instantaneously released because of the fast hydrolysis of the chemical precursor, were the key factor in producing these 3D structures with uniform co-continuous macropores that interconnected directly with the wormlike mesopores. The important characteristic of this procedure is the concurrent formation of a multiscaled porous network. The material exhibits great thermal stability. The hierarchically mesoporous−macroporous Al2O3 obtained is quite attractive for a myriad of applications, from catalysis to biomedicine. The present work illustrates that the one-pot self-formation concept, based on the chemistry of alkyl metals, is a versatile method to design industrially valuable hierarchically porous materials.
Co-reporter:Christophe F. Meunier, Joanna C. Rooke, Alexandre Léonard, Hao Xie and Bao-Lian Su
Chemical Communications 2010 vol. 46(Issue 22) pp:3843-3859
Publication Date(Web):19 Apr 2010
DOI:10.1039/C001799J
This paper reviews our work on the fabrication of photobiochemical hybrid materials via immobilisation of photosynthetically active entities within silica materials, summarising the viability and productivity of these active entities post encapsulation and evaluating their efficiency as the principal component of a photobioreactor. Immobilisation of thylakoids extracted from spinach leaves as well as whole cells such as A. thaliana, Synechococcus and C. caldarium was carried out in situ using sol–gel methods. In particular, a comprehensive overview is given of the efforts to find the most biocompatible inorganic precursors that can extend the lifetime of the organisms upon encapsulation. The effect of matrix–cell interactions on cell lifetime and the photosynthetic efficiency of the resultant materials are discussed. Precursors based on alkoxides, commonly used in “Chimie Douce” to form porous silica gel, release by-products which are often cytotoxic. However by controlling the formation of gels from aqueous silica precursors and silica nanoparticles acting as “cements” one can significantly enhance the life span of the entrapped organelles and cells. Adapted characteristic techniques have shown survival times of up to 5 months with the photosynthetic production of oxygen recorded as much as 17 weeks post immobilisation. These results constitute a significant advance towards the final goal, long-lasting semi-artificial photobioreactors that can advantageously exploit solar radiation to convert polluting carbon dioxide into useful biofuels, sugars or medical metabolites.
Co-reporter:Yu Li, Haiyan Tan, Oleg Lebedev, Jo Verbeeck, Ellen Biermans, G. Van Tendeloo and Bao-Lian Su
Crystal Growth & Design 2010 Volume 10(Issue 7) pp:2969
Publication Date(Web):June 8, 2010
DOI:10.1021/cg100009k
Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57° or 123°. Specifically, a (111) twin plane can only be formed at the interface with a 123° angle. The interfaces formed with a 57° angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design.
Co-reporter:Yu Li, Xiao-Yu Yang, Joanna Rooke, Guastaaf Van Tendeloo, Bao-Lian Su
Journal of Colloid and Interface Science 2010 Volume 348(Issue 2) pp:303-312
Publication Date(Web):15 August 2010
DOI:10.1016/j.jcis.2010.04.052
Ultralong Cu(OH)2 and CuO nanowire bundles with lengths ranging from tens to hundreds of micrometers have been selectively synthesized on a large scale by a facile solution-phase method, using PEG200 as growth-directing agent. The growth mechanisms were investigated by monitoring the nanowire evolution process. The results showed that under the action of PEG200 molecules, the Cu(OH)2 and CuO nanowires were first formed through oriented attachment of colloidal particles, then through side self-assembly leading to nanowire bundles, and finally to CuO nanoleaves. PEG200 plays a critical role in the synthesis of nanowires as it not only prevents the random aggregation of colloidal particles toward CuO nanoleaves but also helps to orientate nanowire growth by the coalescence and alignment in one direction of the colloidal particles. The concentration of OH− in the reaction system is also important for nanowire growth. In the absence of PEG200, nanoleaves are formed by an Ostwald ripening process. The band-gap value estimated from a UV–Vis absorption spectrum of CuO nanowire bundles is 2.32 eV. The photodegradation of a model pollutant, rhodamine B, by CuO nanowires and nanoleaves was compared with commercial nanopowders, showing that the as-synthesized ultralong CuO polycrystalline nanowire bundles have an enhanced photocatalytic activity with 87% decomposition of rhodamine B after an 8-h reaction, which was much higher than that of single-crystal nanoleaves (61%) and commercial nanopowders (32%). The origin of the high photocatalytic activity of these new polycrystalline CuO nanowire bundles has been discussed. This present work reveals that the (0 0 2) crystallographic surface is more favorable for photocatalytic decomposition of organic compounds and that these ultralong CuO nanowire bundles are potential candidates for photocatalysts in wastewater treatment.Variations in nanostructure morphology can give rise to different photocatalytic activities. Oriented nanowires containing a high number of photocatalytically active sites can be selectively synthesized by the addition of structure-directing agents, which affect photocatalytic performance.
Co-reporter:Christophe F. Meunier, Joanna C. Rooke, Kata Hajdu, Pierre Van Cutsem, Pierre Cambier, Alexandre Léonard and Bao-Lian Su
Langmuir 2010 Volume 26(Issue 9) pp:6568-6575
Publication Date(Web):February 10, 2010
DOI:10.1021/la9039286
The encapsulation of living plant cells into materials could offer the possibility to develop new green biochemical technologies. With the view to designing new functional materials, the physiological activity and cellular response of entrapped cells within different silica-based matrices have been assessed. A fine-tuning of the surface chemistry of the matrix has been achieved by the in situ copolymerization of an aqueous silica precursor and a biocompatible trifunctional silane bearing covalently bound neutral sugars. This method allows a facile control of chemical and physical interactions between the entrapped plant cells and the scaffold. The results show that the cell−matrix interaction has to be carefully controlled in order to avoid the mineralization of the cell wall which typically reduces the bioavailability of nutrients. Under appropriate conditions, the introduction of a trifunctional silane (ca. 10%) during the preparation of hybrid gels has shown to prolong the biological activity as well as the cellular viability of plant cells. The relations of cell behavior with some other key factors such as the porosity and the contraction of the matrix are also discussed.
Co-reporter:Arnaud Lemaire and Bao-Lian Su
Langmuir 2010 Volume 26(Issue 22) pp:17603-17616
Publication Date(Web):October 13, 2010
DOI:10.1021/la1033355
A novel yet facile synthesis pathway has been developed for the design of hierarchically structured macro-mesoporous aluminosilicates with high aluminum content at tetrahedral sites using a single molecular bifunctional alkoxide (sec-BuO)2−Al−O-Si(OEt)3 precursor. The use of carboxylate ligands and a highly alkaline media slow down the polymerization rate of the aluminum alkoxide functionality, thus permitting the preservation of the intrinsic Al−O−Si linkage. The hierarchically structured porous aluminosilicate materials present an unprecedented low Si/Al ratio close to 1. Heat treatment applied to the synthesized material seems to favor the incorporation of aluminum into tetrahedral position (intraframework aluminum species). The macro-mesoporosity was spontaneously generated, without the use of any external templating agent, by the hydrodynamic flow of the solvents released during the rapid hydrolysis and condensation processes of this double alkoxide. This method results in materials with an open array of interconnected macrochannels. The synthesized aluminosilicate materials with tailorable macro-mesoporous hierarchy and very high Al content at tetrahedral position hold huge promise in various applications as catalysts, catalysts supports, or adsorbents.
Co-reporter:Jing Liu, Zhi-Yi Hu, Yao Peng, Hua-Wen Huang, Yu Li, Min Wu, Xiao-Xing Ke, Gustaaf Van Tendeloo, Bao-Lian Su
Applied Catalysis B: Environmental (February 2016) Volume 181() pp:138-145
Publication Date(Web):February 2016
DOI:10.1016/j.apcatb.2015.07.054
Co-reporter:Heng Zhao, Min Wu, Jing Liu, Zhao Deng, Yu Li, Bao-Lian Su
Applied Catalysis B: Environmental (5 May 2016) Volume 184() pp:182-190
Publication Date(Web):5 May 2016
DOI:10.1016/j.apcatb.2015.11.018
Co-reporter:Chao Wang, Li Wang, Jun Jin, Jing Liu, Yu Li, Min Wu, Lihua Chen, Binjie Wang, Xiaoyu Yang, Bao-Lian Su
Applied Catalysis B: Environmental (5 July 2016) Volume 188() pp:
Publication Date(Web):5 July 2016
DOI:10.1016/j.apcatb.2016.02.017
•PANI@CdS core-shell nanospheres via a proton doped in-situ polymerization technique.•PANI@CdS core-shell nanospheres demonstrate highly enhanced photocorrosion inhibition and photocatalytic hydrogen production.•CS and/or NCd bonds are newly formed between PANI shell and CdS core, leading to enhanced photocorrosion inhibition.•The photogenerated holes migrate from VB of CdS to HOMO of PANI, leading to enhanced photocatalytic hydrogen production.CdS is a very good visible-light responsive photocatalyst for hydrogen production. However, the fast recombination of photogenerated electron-hole pairs and quick photocorrosion limit its application in photocatalysis. To address these problems, we herein have designed and synthesized monodisperse polyaniline@cadmium sulfide (PANI@CdS) core-shell nanospheres to probe the mechanisms of photocorrosion inhibition and photocatalytic H2 production. All the PANI@CdS core-shell nanospheres demonstrate highly enhanced photocorrosion inhibition and photocatalytic hydrogen production comparing to the pure CdS nanospheres. Particularly, the PANI@CdS core-shell nanospheres with the thinnest PANI shell possess the highest hydrogen production rate of 310 μmol h−1 g−1 in 30 h without deactivation. Our results reveal that the newly formed CS and/or NCd bonds in PANI@CdS prevent the reduction of the surface sulfide ions to sulphur, leading to effective photocorrosion inhibition. Our results also verify that the photogenerated holes migrating from valence band (VB) of CdS to the highest occupied molecular orbital (HOMO) of PANI leads to the enhanced photocatalytic hydrogen production. This work can shed some light on the mechanism of conducting polymers modifying metal sulfides for effective photocorrosion inhibition and highly enhanced photocatalytic activities.
Co-reporter:Nan Jiang, Guo-Liang Ying, Shao-Yin Liu, Ling Shen, Jie Hu, Ling-Jun Dai, Xiao-Yu Yang, Ge Tian and Bao-Lian Su
Chemical Communications 2014 - vol. 50(Issue 97) pp:NaN15410-15410
Publication Date(Web):2014/10/17
DOI:10.1039/C4CC06323F
Amino acid-based biohybrids have been developed to self-assemble on the surface of desulfurizing bacteria to form nanothin and nanoporous shells. The shells not only endow the encapsulated cells with reusability, but also offer platforms to incorporate titania and magnetic nanoparticles to improve the desulfurizing activity and the separation efficiency.
Co-reporter:Christophe F. Meunier, Joanna C. Rooke, Alexandre Léonard, Hao Xie and Bao-Lian Su
Chemical Communications 2010 - vol. 46(Issue 22) pp:NaN3859-3859
Publication Date(Web):2010/04/19
DOI:10.1039/C001799J
This paper reviews our work on the fabrication of photobiochemical hybrid materials via immobilisation of photosynthetically active entities within silica materials, summarising the viability and productivity of these active entities post encapsulation and evaluating their efficiency as the principal component of a photobioreactor. Immobilisation of thylakoids extracted from spinach leaves as well as whole cells such as A. thaliana, Synechococcus and C. caldarium was carried out in situ using sol–gel methods. In particular, a comprehensive overview is given of the efforts to find the most biocompatible inorganic precursors that can extend the lifetime of the organisms upon encapsulation. The effect of matrix–cell interactions on cell lifetime and the photosynthetic efficiency of the resultant materials are discussed. Precursors based on alkoxides, commonly used in “Chimie Douce” to form porous silica gel, release by-products which are often cytotoxic. However by controlling the formation of gels from aqueous silica precursors and silica nanoparticles acting as “cements” one can significantly enhance the life span of the entrapped organelles and cells. Adapted characteristic techniques have shown survival times of up to 5 months with the photosynthetic production of oxygen recorded as much as 17 weeks post immobilisation. These results constitute a significant advance towards the final goal, long-lasting semi-artificial photobioreactors that can advantageously exploit solar radiation to convert polluting carbon dioxide into useful biofuels, sugars or medical metabolites.
Co-reporter:Nan Jiang, Xiao-Yu Yang, Guo-Liang Ying, Ling Shen, Jing Liu, Wei Geng, Ling-Jun Dai, Shao-Yin Liu, Jian Cao, Ge Tian, Tao-Lei Sun, Shi-Pu Li and Bao-Lian Su
Chemical Science (2010-Present) 2015 - vol. 6(Issue 1) pp:NaN491-491
Publication Date(Web):2014/10/17
DOI:10.1039/C4SC02638A
Self-repair is nature's way of protecting living organisms. However, most single cells are inherently less capable of self-repairing, which greatly limits their wide applications. Here, we present a self-assembly approach to create a nanoshell around the cell surface using nanoporous biohybrid aggregates. The biohybrid shells present self-repairing behaviour, resulting in high activity and extended viability of the encapsulated cells (eukaryotic and prokaryotic cells) in harsh micro-environments, such as under UV radiation, natural toxin invasion, high-light radiation and abrupt pH-value changes. Furthermore, an interaction mechanism is proposed and studied, which is successful to guide design and synthesis of self-repairing biohybrid shells using different bioactive molecules.
Co-reporter:Jun Jin, Shao-Zhuan Huang, Jing Liu, Yu Li, Dai-Song Chen, Hong-En Wang, Yong Yu, Li-Hua Chen and Bao-Lian Su
Journal of Materials Chemistry A 2014 - vol. 2(Issue 25) pp:NaN9708-9708
Publication Date(Web):2014/04/28
DOI:10.1039/C4TA01775G
As anode materials for lithium ion batteries, two three dimensionally ordered macroporous TiO2, one with disordered inter-particle mesopores formed by the aggregation of nanoparticles (3DOM) and another with inner-particle mesopores generated by a surfactant templating strategy (3DOMM), have been synthesized using poly(styrene-methyl methacrylate-3-sulfopropyl methacrylate potassium) (P(St-MMA-SPMAP)) spheres as a hard template and their electrochemical properties are compared. SEM and TEM observations reveal that both 3DOM TiO2 and 3DOMM TiO2 have well-ordered macropores and interconnected macropore walls with a regular periodicity. 3DOMM TiO2 demonstrates a specific surface area of 139 m2 g−1, which is higher than that of 3DOM TiO2 (99 m2 g−1) due to the smaller crystallite size and inner-particle mesopores. The electrolyte adsorption results show that both 3DOM TiO2 and 3DOMM TiO2 have similar adsorption capacities despite a difference in the surface area. Electrochemical impendence spectroscopy analysis shows that 3DOMM TiO2 has a lower charge transfer resistance and faster Li+ diffusion coefficient than 3DOM TiO2. Moreover, both 3DOM TiO2 and 3DOMM TiO2 possess excellent initial capacity of 248 mA h g−1 and 235 mA h g−1 at 0.2 C and 208 mA h g−1 and 202 mA h g−1 at 1 C, respectively. The reversibility study demonstrates that the 3DOMM TiO2 displays higher cycling capacity, superior rate behavior and higher Coulombic efficiency because the higher surface area provides more active sites and the presence of the inner-particle mesopores in the walls of macropores serve as a bicontinuous transport path and affords a shorter path length for diffusion of Li ions compared with the 3DOM TiO2 and its crystallite aggregated mesopores. The reversible capacity of 106 mA h g−1 observed for the 3DOMM TiO2 can be retained after 200 charge–discharge cycles at a relatively high current rate of 4 C. This cycle stability performance can be equally attributed to the crystallite size and inner-particle mesopores in the 3DOMM TiO2. Moreover, the existence of a bicontinuous porous structure in the 3DOMM TiO2 can further enhance the lithium insertion/extraction capacity at high rates. We believe that this study can shed light on the 3DOMM structure as a promising material for highly enhanced performance in lithium ion batteries.
Co-reporter:Shao-Zhuan Huang, Yi Cai, Jun Jin, Yu Li, Xian-Feng Zheng, Hong-En Wang, Min Wu, Li-Hua Chen and Bao-Lian Su
Journal of Materials Chemistry A 2014 - vol. 2(Issue 34) pp:NaN14108-14108
Publication Date(Web):2014/06/25
DOI:10.1039/C4TA02339K
Low electron transportation and lithium ion diffusion coefficient in laminar vanadium oxide nanostructures limit their electrochemical performance for lithium ion batteries. In this work, V2O5 nanowires and VOx nanotubes were obtained via heat treatment of the pristine vanadium oxide nanotubes at different temperatures under air and nitrogen atmospheres, respectively, and then used as cathode materials for lithium ion batteries. It is interesting to note that the pristine vanadium nanotubes were transformed to V2O5 nanowires under an ambient atmosphere while the nanotube morphology can be maintained under an inert N2 atmosphere. The electrochemical results show that the V2O5 nanowires obtained at 400 °C deliver the best cycling performance with an initial discharge capacity as high as 278 mA h g−1 and the best rate capability with a discharge capacity of 115 mA h g−1 at 500 mA g−1. The VOx nanotubes obtained at 400 °C show the highest lithium storage capacity of 218 mA h g−1 with excellent capability retention and the best rate capability among all the nanotube samples. The improvement of electrochemical properties of V2O5 nanowires and VOx nanotubes can be attributed to the synergy of the enhanced surface area and better crystallinity. The different electrochemical properties reveal the existence of four different modes of Li ion intercalation/de-intercalation behaviors in V2O5 nanowires and VOx nanotubes. It is very interesting to note that the Li ion intercalation/de-intercalation in amorphous VOx nanotubes (VOx + yLi+ + ye− → LiyVOx) can induce a phase transformation from amorphous matrix to layered crystalline structure. This present work reveals that the electrochemical properties, in particular the cycling stability of vanadium oxide nanostructures, can be improved by tuning the one-dimensional structures' crystallinity. Furthermore, the phase transformation from amorphous matrix to layered crystalline structure of VOx nanotubes may open an exciting door for all the amorphous nanostructures for the application of LIBs.
Co-reporter:Meryam Zalfani, Benoit van der Schueren, Zhi-Yi Hu, Joanna C. Rooke, Ramzi Bourguiga, Min Wu, Yu Li, Gustaaf Van Tendeloo and Bao-Lian Su
Journal of Materials Chemistry A 2015 - vol. 3(Issue 42) pp:NaN21256-21256
Publication Date(Web):2015/09/08
DOI:10.1039/C5TA00783F
Novel 3DOM BiVO4/TiO2 nanocomposites with intimate contact were for the first time synthesized by a hydrothermal method in order to elucidate their visible-light-driven photocatalytic performances. BiVO4 nanoparticles and 3DOM TiO2 inverse opal were fabricated respectively. These materials were characterized by XRD, XPS, SEM, TEM, N2 adsorption–desorption and UV-vis diffuse (UV-vis) and photoluminescence spectroscopies. As references for comparison, a physical mixture of BiVO4 nanoparticles and 3DOM TiO2 inverse opal powder (0.08:1), and a BiVO4/P25 TiO2 (0.08:1) nanocomposite made also by the hydrothermal method were prepared. The photocatalytic performance of all the prepared materials was evaluated by the degradation of rhodamine B (RhB) as a model pollutant molecule under visible light irradiation. The highly ordered 3D macroporous inverse opal structure can provide more active surface areas and increased mass transfer because of its highly accessible 3D porosity. The results show that 3DOM BiVO4/TiO2 nanocomposites possess a highly prolonged lifetime and increased separation of visible light generated charges and extraordinarily high photocatalytic activity. Owing to the intimate contact between BiVO4 and large surface area 3DOM TiO2, the photogenerated high energy charges can be easily transferred from BiVO4 to the 3DOM TiO2 support. BiVO4 nanoparticles in the 3DOM TiO2 inverse opal structure act thus as a sensitizer to absorb visible light and to transfer efficiently high energy electrons to TiO2 to ensure long lifetime of the photogenerated charges and keep them well separated, owing to the direct bandgap of BiVO4 of 2.4 eV, favourably positioned band edges, very low recombination rate of electron–hole pairs and stability when coupled with photocatalysts, explaining the extraordinarily high photocatalytic performance of 3DOM BiVO4/TiO2 nanocomposites. It is found that larger the amount of BiVO4 in the nanocomposite, longer the duration of photogenerated charge separation and higher the photocatalytic activity. This work can shed light on the development of novel visible light responsive nanomaterials for efficient solar energy utilisation by the intimate combination of an inorganic light sensitizing nanoparticle with an inverse opal structure with high diffusion efficiency and high accessible surface area.
Co-reporter:Joanna Claire Rooke, Alexandre Léonard, Hugo Sarmento, Christophe F. Meunier, Jean-Pierre Descy and Bao-Lian Su
Journal of Materials Chemistry A 2011 - vol. 21(Issue 4) pp:NaN959-959
Publication Date(Web):2010/11/11
DOI:10.1039/C0JM02712J
A photosynthetic bioreactor for CO2 assimilation has been designed using silica sol–gel immobilisation technologies with the chlorophyta Botryococcus braunii (Kützing) and Chlorella vulgaris (Beijerinck). The living hybrid gels formed revealed a mesoporosity that enabled diffusion of nutrients and gases, promoting the light and dark photosynthetic reactions from within the bulk of the material. To determine the efficiency of the photosynthetic bioreactor in terms of CO2 remediation, the activity and viability of the encapsulated cells have been monitored through oximetry, 14C assimilation, pulse amplitude modulation fluorimetry and confocal microscopy, revealing a long term productivity of living hybrid materials capable of photosynthetic processes for at least 80 days. Structural and textural properties of the gels were established through 29Si MASNMR and N2 physisorption respectively.
Co-reporter:Xiao-Yu Yang, Alexandre Léonard, Arnaud Lemaire, Ge Tian and Bao-Lian Su
Chemical Communications 2011 - vol. 47(Issue 10) pp:NaN2786-2786
Publication Date(Web):2011/01/18
DOI:10.1039/C0CC03734F
In this paper, we will thoroughly review a novel and versatile self-formation phenomenon that can be exploited to target porous hierarchies of materials without need of any external templates only on the basis of the chemistry of metal alkoxides and alkylmetals. These hierarchically porous materials have unique structures, which are made of either parallel funnel-like/straight macrochannels or 3D continuous interconnected macroporous foams with micro/mesoporous walls. The self-generated porogen mechanism has been proposed, leading to a series of techniques to tailor porous hierarchy, i.e. the use of different chemical precursors (single metal alkoxides, mixed metal alkoxides, single molecular precursors with two different alkoxide functionalities, alkylmetals, etc., …), the control of their hydrolysis and condensation rates (pH, chelating agents,…) and the addition of alkoxysilanes as co-reactant. Various chemical compositions from single or binary metal oxides, to aluminosilicates, aluminophosphates, silicoaluminophosphates, metallophosphates,… can be prepared, offering a panel of potential applications. Some perspectives have been proposed to transform the synthesized materials with a hierarchy of pore sizes to micro–meso–macroporous crystalline materials with zeolite architectures. The advantages of this self-formation preparation method have been discussed compared to traditional templating methods. The possibility to combine with other strategies, for example soft or hard templating, to target even more sophisticated hierarchically meso–macroporous materials with specific structure and function for various applications has been presented. The “hierarchical catalysis” concept has been re-visited.
Co-reporter:Ming-Hui Sun, Shao-Zhuan Huang, Li-Hua Chen, Yu Li, Xiao-Yu Yang, Zhong-Yong Yuan and Bao-Lian Su
Chemical Society Reviews 2016 - vol. 45(Issue 12) pp:NaN3563-3563
Publication Date(Web):2016/06/03
DOI:10.1039/C6CS00135A
Over the last decade, significant effort has been devoted to the applications of hierarchically structured porous materials owing to their outstanding properties such as high surface area, excellent accessibility to active sites, and enhanced mass transport and diffusion. The hierarchy of porosity, structural, morphological and component levels in these materials is key for their high performance in all kinds of applications. The introduction of hierarchical porosity into materials has led to a significant improvement in the performance of materials. Herein, recent progress in the applications of hierarchically structured porous materials from energy conversion and storage, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine is reviewed. Their potential future applications are also highlighted. We particularly dwell on the relationship between hierarchically porous structures and properties, with examples of each type of hierarchically structured porous material according to its chemical composition and physical characteristics. The present review aims to open up a new avenue to guide the readers to quickly obtain in-depth knowledge of applications of hierarchically porous materials and to have a good idea about selecting and designing suitable hierarchically porous materials for a specific application. In addition to focusing on the applications of hierarchically porous materials, this comprehensive review could stimulate researchers to synthesize new advanced hierarchically porous solids.
Co-reporter:Alexandre Léonard, Philippe Dandoy, Emeric Danloy, Grégory Leroux, Christophe F. Meunier, Joanna C. Rooke and Bao-Lian Su
Chemical Society Reviews 2011 - vol. 40(Issue 2) pp:NaN885-885
Publication Date(Web):2011/01/07
DOI:10.1039/C0CS00024H
This critical review highlights the advances that have been made over recent years in the domain of whole-cell immobilisation and encapsulation for applications relating to the environment and human health, particularly focusing on examples of photosynthetic plant cells, bacteria and algae as well as animal cells. Evidence that encapsulated photosynthetic cells remain active in terms of CO2 sequestration and biotransformation (solar driven conversion of CO2 into biofuels, drugs, fine chemicals etc.), coupled with the most recent advances made in the field of cell therapy, reveals the need to develop novel devices based on the preservation of living cells within abiotic porous frameworks. This review shall corroborate this statement by selecting precise examples that unambiguously demonstrate the necessity and the benefits of such smart materials. As will be described, the handling and exploitation of photosynthetic cells are enhanced by entrapment or encapsulation since the cells are physically separated from the liquid medium, thereby facilitating the recovery of the metabolites produced. In the case of animal cells, their encapsulation within a matrix is essential in order to create a physical barrier that can protect the cells auto-immune defenders upon implantation into a living body. For these two research axes, the key parameters that have to be kept in mind when designing hybrid materials will be identified, concentrating on essential aspects such as biocompatibility, mechanical strength and controlled porosity (264 references).
Co-reporter:Min Yan, Yang Zhang, Yu Li, Yongqi Huo, Yong Yu, Chao Wang, Jun Jin, Lihua Chen, Tawfique Hasan, Binjie Wang and Bao-Lian Su
Journal of Materials Chemistry A 2016 - vol. 4(Issue 24) pp:NaN9412-9412
Publication Date(Web):2016/05/16
DOI:10.1039/C6TA03211G
Lithium–sulfur (Li–S) batteries are receiving significant attention as an alternative power system for advanced electronic devices because of their high theoretical capacity and energy density. In this work, we have designed manganese dioxide (MnO2) nanosheet functionalized sulfur@poly(3,4-ethylenedioxythiophene) core–shell nanospheres (S@PEDOT/MnO2) for high performance lithium–sulfur (Li–S) batteries. A PEDOT layer is used to address the low electrical conductivity of sulfur and acts as a protective layer to prevent dissolution of polysulfides. The MnO2 nanosheets functionalized on PEDOT further provide a high active contact area to enhance the wettability of the electrode materials with electrolytes and further interlink the polymer chains to improve the conductivity and stability of the composite. As a result, S@PEDOT/MnO2 exhibits an improved capacity of 827 mA h g−1 after 200 cycles at 0.2C (1C = 1673 mA g−1) and a further ∼50% enhancement compared to S@PEDOT (551 mA h g−1) without MnO2 functionalization. In particular, the discharge capacity of S@PEDOT/MnO2 is 545 mA h g−1 after 200 cycles at 0.5C. Our demonstration here indicates that the functionalization of inorganic nanostructures on conducting polymer coated sulfur nanoparticles is an effective strategy to improve the electrochemical cycling performance and stability of sulfur cathodes for Li–S batteries.
Co-reporter:Shao-Zhuan Huang, Yi Cai, Jun Jin, Jing Liu, Yu Li, Hong-En Wang, Li-Hua Chen, Tawfique Hasan and Bao-Lian Su
Journal of Materials Chemistry A 2016 - vol. 4(Issue 11) pp:NaN4272-4272
Publication Date(Web):2016/02/16
DOI:10.1039/C6TA00594B
Unique walnut-shaped porous MnO2/carbon nanospheres (P-MO/C-NSs) with high monodispersity have been designed and prepared for lithium storage via in situ carbonization of amorphous MnO2 nanospheres. Polyvinylpyrrolidone (PVP) is utilized as both the surfactant for morphology control and carbon source for carbon scaffold formation accompanied with MnO2 crystallization. Such a unique walnut-shaped porous nanostructure with an intimate carbon layer provides a large contact area with the electrolyte, short transport path length for Li+, low resistance for charge transfer and superior structural stability. The P-MO/C-NS electrode demonstrates high lithium storage capacity (1176 mA h g−1 at 100 mA g−1), very good cycling stability (100% capacity retention versus the second cycle) and excellent rate capability (540 mA h g−1 at 1000 mA g−1). We propose that it is the deep oxidation of Mn2+ to Mn3+ in P-MO/C-NSs, which results in an extraordinarily high capacity of 1192 mA h g−1 at a current density of 1000 mA g−1 after a long period of cycling, very close to the maximum theoretical reversible capacity of MnO2 (1230 mA h g−1). This is the highest value ever observed for MnO2-based electrodes at such a rate. The high lithium storage capacity and rate capability can be attributed to the enhanced reaction kinetics owing to the walnut-shaped porous nanostructure with an intimate carbon layer. This work provides a meaningful demonstration of designing porous nanostructures of carbon-coated metal oxides undergoing deep conversion reactions for enhanced electrochemical performances.
