Co-reporter:Xiaobo Huang, Qing Wang, Dong Jiang, Yongmin Huang
Catalysis Communications 2017 Volume 100(Volume 100) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.catcom.2017.06.045
•NC, NPC and BNC samples were fabricated via a facile synthesis.•The hybrids possessed 3D macro/meso/microporous carbon structure.•BNC performed better electrochemical activity than NC and NPC.•The synergy of dual doping and porous structure for BNC boosted ORR and OER.Heteroatom (B, N) co-doped three-dimensional (3D) porous graphitic carbon made from methyl violet and boric acid are fabricated via a super simple synthesis using silicon sphere as the hard-template. The 3D structure of as-prepared samples are analyzed by TEM, XRD and XPS. As resulted, the activity of BNC-800-800 in ORR and OER is better than sole-doped (NC-800) and dual-doped (NPC-800) hybrids. The strong synergistic effect with 3D porous structure, dual doping and high amount of pyridinic and pyrrolic nitrogen endows BNC-800 catalyst with an outstanding activity toward ORR and improved OER performance to commercial Pt/C catalyst under alkaline condition.Download high-res image (79KB)Download full-size image
Co-reporter:Qing Wang, Wenhui Hu, Yongmin Huang
International Journal of Hydrogen Energy 2017 Volume 42, Issue 9(Volume 42, Issue 9) pp:
Publication Date(Web):2 March 2017
DOI:10.1016/j.ijhydene.2017.02.038
•A series of Co-N/G samples are fabricated by one-pot hydrothermal synthesis.•Triaminopyrimidine as nitrogen precursor anchor cobalt oxides on graphene oxide.•The interaction between cobalt oxides and N-graphene of Co-N/G 600 boost ORR and OER.A series of efficient bifunctional electrocatalyst composed of nitrogen-doped graphene-cobalt oxide nanoparticles nano-hybrids (Co-N/G) are fabricated by one-pot hydrothermal synthesis, which involves in-situ growth of cobalt oxides nanocrystals and nitrogen doping into graphene. 2, 4, 6-Triaminopyrimidine used as nitrogen precursor could anchor cobalt oxides nanoparticles on graphene oxide as active centers for oxygen electrode reactions. The TEM, Raman, XRD and XPS confirm the germination of nitrogen doped graphene and nano-sized cobalt oxides. The optimized Co-N/G catalyst consists of the highest contents of pyridinic nitrogen and CoO, which efficiently catalyze both ORR and OER. The strong coupling between cobalt oxides and N-graphene endows Co-N/G 600 with a low reversible overvoltage of 0.96 V between ORR and OER in alkaline medium, which is superior to novel catalysts such as Pt/C (1.24 V), IrO2 (1.43 V) and RuO2 (1.35 V), rendering it bi-catalyst efficient and economical for reversible oxygen electrode reactions.
Co-reporter:Zhiwei Cui, Yongmin Huang, Honglai Liu
Journal of the Mechanical Behavior of Biomedical Materials 2017 Volume 71(Volume 71) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.jmbbm.2017.02.014
In this work, a micromechanical study using the lattice spring model (LSM) was performed to predict the mechanical properties of BPMs by simulation of the Brazilian test. Stress-strain curve and Weibull plot were analyzed for the determination of fracture strength and Weibull modulus. The presented model composed of linear elastic elements is capable of reproducing the non-linear behavior of BPMs resulting from the damage accumulation and provides consistent results which are in agreement with experimental measurements. Besides, it is also found that porosity shows significant impact on fracture strength while pore size dominates the Weibull modulus, which enables us to establish how choices made in the microstructure to meet the demand of brittle porous materials functioning in various operating conditions.
Co-reporter:Qing Wang, Xin Qiu, Wenhui Hu, Yongmin Huang
Materials Letters 2017 Volume 190(Volume 190) pp:
Publication Date(Web):1 March 2017
DOI:10.1016/j.matlet.2016.12.117
•A series of Co/NC samples were fabricated via a facile synthesis.•The Co/NC samples possessed 3D macro/mesoporous carbon structure.•Methyl red was selected as carbon and nitrogen precursor.•The synergy of Co3O4 core and N-graphite shell for Co/NC-800 boosted ORR and OER.A series of bifunctional electrocatalysts Co/NC-n (n = temperature) consist of three-dimensional (3D) porous nitrogen doped carbon supported Co3O4 via a super simple synthesis. Methyl red is selected as carbon and nitrogen precursor, cobalt (II) acetate as cobalt sources, and silicon sphere as hard-template. The presence of 3D Co3O4/N-doped macro/mesoporous carbon structure can be verified by TEM, XRD and XPS. The unique pore structure, strong confinement effect between Co3O4 core and N-graphitic shell and the high composition of pyridinic nitrogen doping endows Co/NC-800 catalyst excellent oxygen reduction reaction performance and improved oxygen evolution reaction activity to commercial Pt/C catalyst under alkaline environment.
Co-reporter:Lan Gao, Taoping Liu, Xiaochun Tao, Yongmin Huang
Tetrahedron Letters 2016 Volume 57(Issue 44) pp:4905-4909
Publication Date(Web):2 November 2016
DOI:10.1016/j.tetlet.2016.09.061
•Green and practical synthetic approaches with easy operation.•Excellent activity and selectivity.•Homogeneous catalyst with a self-separation feature.•The catalyst is reusable up to ten times without any significant loss of activity.An eco-friendly and readily accessible 2,2,6,6-tetramethylpiperidinium triflate was found as highly-selective and self-separated catalyst for esterification under solvent-free condition. The X-ray crystallography revealed that it formed a ‘hydrophobic wall’ which could effectively eliminate the generated water from the reactive sites. Moreover, it could precipitate from the reaction system with excellent recovery ratio (>99%) and be reused for ten times without any significant loss of activity.
Co-reporter:Haojun Huang, Qing Wang, Qinglian Wei, YongMin Huang
International Journal of Hydrogen Energy 2015 Volume 40(Issue 18) pp:6072-6084
Publication Date(Web):18 May 2015
DOI:10.1016/j.ijhydene.2015.02.089
•Copolymer based N-doped mesoporous carbon (NMC) with high BET surface is developed.•CoO/NMCs hybrid catalysts (CoNMC) show an efficient ORR activity in alkaline media.•The catalytic activities are due to the high surface area and synergetic effect.The nitrogen doped mesoporous carbon (NMC) derived from pyrrole-co-furfural copolymer has been successfully developed by using an SBA-15 template. The as-prepared NMCs possess well-defined mesoporous structures with a narrow pore size distribution, high porosity and large surface area (up to ∼1812 m2 g−1). Using NMC as the supports, a hybrid catalyst of CoO nanoparticles loaded on NMCs (CoNMC) were prepared for the electrocatalytic oxygen reduction reaction (ORR) in alkaline media. The optimized CoNMC catalyst exhibits efficient catalytic activity with a four-electron reaction pathway and superior stability to the commercial Pt/C electrocatalyst. Furthermore, the high catalytic activity of CoNMC catalysts are mainly attributed to the high surface area and the synergetic effect between the N-doped carbon supports and cobalt oxides.
Co-reporter:Guangyu MU, Qinglian WEI, Yongmin HUANG
Journal of Rare Earths 2015 Volume 33(Issue 12) pp:1329-1334
Publication Date(Web):1 December 2015
DOI:10.1016/S1002-0721(14)60565-2
CeO2 hollow microspheres were prepared through a facile method by using yeast cells as bio-templates. The yeast provided a solid frame for the deposition of cerium hydroxide to form the hybrid Ce(OH)3@yeast precursor. The resulting CeO2 hollow microspheres were obtained by calcining the precursor. The products were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FTIR), N2 adsorption/desorption analysis, X-ray photoelectron spectrum (XPS) and H2 temperature programmed reduction (H2-TPR). It was found that the products fully retained the morphology of the yeast cells and the size of the hollow microspheres was about 1.5–2 μm. The catalytic test results showed that the as-obtained hollow CeO2 microspheres possessed a higher catalytic activity in CO oxidation than the commercial CeO2, which attributed to their higher surface area, hollow structure and superior reducibility. This study provided a promising route for the preparation of a variety of other inorganic hollow microspheres.FE-SEM images of original yeast templates (a), Ce(OH)3@yeast hybrid microspheres (b), as-prepared CeO2 (c) and broken CeO2 microspheres (d)
Co-reporter:Yuan Ma, Qinglian Wei, Ruowen Ling, Fengkai An, Guangyu Mu, Yongmin Huang
Microporous and Mesoporous Materials 2013 Volume 165() pp:177-184
Publication Date(Web):1 January 2013
DOI:10.1016/j.micromeso.2012.08.016
Co-reporter:M. Nie, Y.C. Zou, Y.M. Huang, J.Q. Wang
International Journal of Hydrogen Energy 2012 Volume 37(Issue 2) pp:1568-1576
Publication Date(Web):January 2012
DOI:10.1016/j.ijhydene.2011.10.006
A series of Ni–Fe–B catalysts with different Fe/(Fe + Ni) molar ratios, used for the hydrolysis of NaBH4, were prepared by chemical reduction of NiCl2 and FeCl3 mixed solution with NaBH4. The measurements revealed that the catalysts with the molar ratio of Fe/(Fe + Ni) (30%) exhibited the highest catalytic activity, and the optimal reduction temperature is 348 K. In addition, the effects of the concentration of NaBH4, NaOH and the hydrolytic temperature of NaBH4 were discussed in detail. The results show that the reaction rate of hydrolysis first rises up and then goes down subsequently with the increase of NaBH4 concentration, as well as the concentration of NaOH. The activation energy of the hydrolysis for Ni–Fe–B catalysts is fitted to 57 kJ/mol. The maximum value of hydrogen generation is 2910 ml/(min g) at 298 K.Highlights► Small amount of doped-Fe has a positive effect. ► Ni–Fe–B catalysts with Fe/(Fe + Ni) molar ratio equaling to 30% show the best activity. ► Catalysts prepared at 348 K perform better than that at lower temperature.
Co-reporter:Xiuhua Jin;Qinglian Wei;Haojun Huang;Mengxue Wang
Chinese Journal of Chemistry 2012 Volume 30( Issue 12) pp:2805-2812
Publication Date(Web):
DOI:10.1002/cjoc.201200987
Abstract
Nanoporous carbon/graphene composites (NCGC) are synthesized via one-step hydrothermal approach combining carbonization, where phenol and formaldehyde are used as carbon sources and triblock copolymers F127 as template. Transmission electron microscopy (TEM) and nitrogen adsorption measurements show that the synthesized NCGC samples possess high surface area over 400 m2·g−1 and mesoporous structures with interconnected pores. The electrochemical studies demonstrate that Pt catalyst with NCGC as support exhibits better eletrocatalytic activity for methanol oxidation as compared to the catalyst taking widely-used VulcanXC-72 as support. In addition, the potential formation mechanism of NCGC is discussed.
Co-reporter:Y.C. Zou, M. Nie, Y.M. Huang, J.Q. Wang, H.L. Liu
International Journal of Hydrogen Energy 2011 Volume 36(Issue 19) pp:12343-12351
Publication Date(Web):September 2011
DOI:10.1016/j.ijhydene.2011.06.138
In this work, different shapes (powder and spherical) of ruthenium-active carbon catalysts (Ru/C) were prepared by impregnation reduction method for hydrogen generation (HG) from the hydrolysis reaction of the alkaline NaBH4 solution. The effects of temperature, amount of catalysts, and concentration of NaOH and NaBH4 on the hydrolysis of NaBH4 solution were investigated with different shapes of Ru/C catalysts. The results show that the HG kinetics of NaBH4 solution with the powder Ru/C catalysts is completely different from that with the spherical Ru/C catalysts. The main reason is that both mass and heat transfer play important roles during the reaction with Ru/C catalysts. The HG overall kinetic rate equations for NaBH4 hydrolysis using the powder Ru/C catalysts and the spherical catalysts are described as r = A exp (−50740/RT) [catalyst]1.05 [NaOH]−0.13 [NaBH4]−0.25 and r = A exp (−52,120/RT) [catalyst]1.00 [NaOH]−0.21 [NaBH4]0.27 respectively.Highlights► Kinetics of NaBH4 hydrolysis on powder Ru/C and spherical Ru/C catalysts. ► NaOH has a negative effect on H2 generation (HG) rate with Ru/C catalysts. ► HG rate of powder Ru/C catalysts decreases while NaBH4 concentration increases. ► HG rate of spherical Ru/C catalysts increases at first and then decreases. ► The main reason is the competition between mass and heat transfer.
Co-reporter:Y.C. Zou, Y.M. Huang, X. Li, H.L. Liu
International Journal of Hydrogen Energy 2011 Volume 36(Issue 7) pp:4315-4322
Publication Date(Web):April 2011
DOI:10.1016/j.ijhydene.2011.01.027
Ru-active carbon (Ru/C) catalysts are prepared by impregnation reduction method for hydrogen generation via hydrolysis of alkaline sodium borohydride (NaBH4) solution. The corresponding activity and durability of the prepared catalysts are tested in an immobile bed reactor. The variation of hydrogen generation rate with the increasing of flux and concentration of NaBH4 solution is measured. The durability of the catalysts prepared under various reductive pH values and reductants is tested by using different concentrations of NaBH4 solution (10 & 15 wt%). It is found that the durability of catalyst in 15 wt% NaBH4 solution is longer than that in 10 wt% NaBH4 solution. The deactivation of Ru/C catalysts is considered as the comprehensive effect of three factors: the loss of Ru, the deposition of byproducts on the catalyst surface and the aggregation of Ru particles.
Co-reporter:Xingqing Xiao;Jian Feng;Honglai Liu;Ying Hu
Macromolecular Theory and Simulations 2011 Volume 20( Issue 2) pp:124-132
Publication Date(Web):
DOI:10.1002/mats.201000064
Co-reporter:Xingqing Xiao;Jian Feng;Honglai Liu;Ying Hu
Macromolecular Theory and Simulations 2011 Volume 20( Issue 2) pp:
Publication Date(Web):
DOI:10.1002/mats.201190002
Co-reporter:Xia Chao Jin, Yong Min Huang, Hong Lai Liu
Chinese Chemical Letters 2009 Volume 20(Issue 3) pp:366-369
Publication Date(Web):March 2009
DOI:10.1016/j.cclet.2008.11.036
Polyvinyl alcohol/polyacrylamide semi-interpenetrated hydrogels were prepared via freeze–thaw process. When a 20 V of DC was applied across the gels, the gels with lower polyacrylamide content underwent a contraction or partly turned into solution, while for the gels with higher polyacrylamide concentration, a complete gel–sol transition was observed in a short time.
Co-reporter:Xiachao Jin;Hongmei Kang;Honglai Liu;Ying Hu
Journal of Applied Polymer Science 2008 Volume 110( Issue 6) pp:3690-3696
Publication Date(Web):
DOI:10.1002/app.28982
Abstract
A series of electric field sensitive copolymer P(AA-co-AAEM) gels of acrylic acid (AA) with acetoacetoxy ethyl methacrylate (AAEM) were prepared by free-radical copolymerization, with N,N′-methylene bisacrylamide (MBAAm) and ammounium persulfate (APS) as crosslinking agent and initiator, respectively. The structures and properties of the gels were tunable by changing the monomer feed weighty ratio (R) (R = WAAEM/(WAAEM + WAA) of AAEM and AA. The influences of the NaCl concentration and pH buffer solutions on the equilibrium swelling ratios of the gels were studied in detail. It is shown that both NaCl concentration and pH value of the buffer solution affect the swelling properties of the P(AA-co-AAEM) gels greatly. Moreover, the gel deswelling behavior induced by a direct current electric field was investigated and an excellent electric-sensitivity was found. Among all the samples, the gel with monomer feed weighty ratio (R) = 0.1479 showed the best electrical contraction properties. On the basis of the experimental results, the mechanism of the electricity-induced deswelling behavior was presented. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Co-reporter:Weijun Liu, Yongmin Huang, Honglai Liu, Ying Hu
Journal of Colloid and Interface Science 2007 Volume 313(Issue 1) pp:117-121
Publication Date(Web):1 September 2007
DOI:10.1016/j.jcis.2007.04.022
Poly(N-isopropylacrylamide)/chitosan (PNIPAM/CS) core–shell microgel was synthesized by graft copolymerization. The microstructure of copolymers was characterized by FT-IR spectrum and 1H-nuclear magnetic resonance (1H NMR). Transmission electron microscope (TEM) and dynamic light scattering (DLS) measurements display that the microgel has high monodispersity and with a core–shell structure. For swelling the microgel in various alcohol solutions, the particles first shrink; then flocculation occurs resulted from weak aggregation of particles with the increase of alcohol concentration. The investigation of the size of microgels as a function of temperature shows that the thermo-sensitive property is markedly exhibited when the alcohol concentration is low, and vanishes when the alcohol concentration exceeds some value where the microgels have the lowest size.Poly(N-isopropylacrylamide)/chitosan (PNIPAM/CS) core–shell microgel was synthesized by graft copolymerization. The microstructure of copolymer was characterized by FT-IR spectrum and 1H-nuclear magnetic resonance (1H NMR). For swelling the microgel in various alcohol solutions, the particles first shrink and then flocculate when alcohol was increased to certain concentration. The investigation of the microgels size with temperature shows that the thermo-sensitive property is markedly exhibited when the alcohol concentration is lower, and vanishes while the alcohol concentration exceeds some value where the microgels have the lowest size.
Co-reporter:Honglai Liu;Xingqing Xiao;Ying Hu
Macromolecular Theory and Simulations 2007 Volume 16(Issue 8) pp:732-741
Publication Date(Web):17 OCT 2007
DOI:10.1002/mats.200700041
The morphology transitions in AB diblock and ABA triblock copolymers confined between flat and curved surfaces were investigated by MC simulations. Upon variation of the extent of frustration between thickness d and bulk lamellae period L0, parallel and vertical or distorted vertical lamellar structures appear in both flat and curved confinements. With increasing curvature, the compatibility of d and L0 becomes more perturbed so that perfectly parallel lamellae are formed with increasing difficulty. Owing to the smaller L0 of ABA as compared to AB, the transformation frequency of the incompatible region of d/L0(ABA) is more notable for ABA and the corresponding transformation period is larger than that of AB.
Co-reporter:Xuezhe ZHAO, Shengwei DENG, Yongmin HUANG, Honglai LIU, Ying HU
Chinese Journal of Chemical Engineering (August 2011) Volume 19(Issue 4) pp:549-557
Publication Date(Web):1 August 2011
DOI:10.1016/S1004-9541(11)60020-7
The effects of blend composition and micro-phase structure on the mechanical behavior of A/B polymer blend film are studied by coupling the Monte Carlo (MC) simulation of morphology with the lattice spring model (LSM) of micro mechanics of materials. The MC method with bond length fluctuation and cavity diffusion algorithm on cubic lattice is adopted to simulate the micro-phase structure of A/B polymer blend. The information of morphology and structure is then inputted to the LSM composed of a three-dimensional network of springs to obtain the mechanical properties of polymer blend film. Simulated results show that the mechanical response is mainly affected by the density and the composition of polymer blend film through the morphology transition. When a force is applied on the outer boundary of polymer blend film, the vicinity of the inner cavities experiences higher stresses and strains responsible for the onset of crack propagation and the premature failure of the entire system.
Co-reporter:Wenhui Hu, Qing Wang, Shanshan Wu and Yongmin Huang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 43) pp:NaN16927-16927
Publication Date(Web):2016/09/26
DOI:10.1039/C6TA08103G
The development of future energy technology relies deeply on the design of cheap, sustainable and efficient systems for energy conversion and storage. As for the widespread oxygen electrode reactions, exploiting high efficiency and stable catalysts to boost both oxygen reduction (ORR) and evolution reactions (OER) seems to be a paramount mission. Here, we report a nitrogen-doped mesoporous carbon material with cobalt oxide nanoparticles encapsulated in the graphitic layers via a facile one-pot synthesis. Strikingly, the as-fabricated Co–N/C 800 affords a low reversible overvoltage of 0.96 V between ORR and OER, surpassing 270, 390 and 460 mV in potential over 20 wt% Pt/C, RuO2 and IrO2, which makes it a high performance non-precious metal bicatalyst for reversible oxygen electrode reactions.
