The Experts below are selected from a list of 86292 Experts worldwide ranked by ideXlab platform
Weixin Huang - One of the best experts on this subject based on the ideXlab platform.
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effect of particle shape and electrolyte cation on co adsorption to copper oxide nanoparticle electrocatalysts
Journal of Physical Chemistry C, 2018Co-Authors: Matthew M Sartin, Zongyou Yu, Wei Chen, Fan He, Yanxia Chen, Weixin HuangAbstract:Cu2O-derived nanoparticles are efficient catalysts for the electrochemical conversion of CO and CO2 to multicarbon products. Generation of multicarbon products requires dimerization of adsorbed CO, which is accelerated when the coverage of CO is high. The electrolyte cation and the initially exposed Crystal Plane of the catalyst both affect the reaction rate, but the relation between these effects and CO coverage is unclear, especially given the surface reconstruction that occurs during reduction reactions on Cu2O. We prepared a series of shape-controlled Cu2O nanoparticles with similar sizes but different initially exposed Crystal Planes [cubes (100), octahedra (111), and dodecahedra (110)], and we used the infrared absorption bands detected in situ to compare the potential-dependent CO coverage on each of the nanomaterials in CO-saturated 0.1 M NaHCO3 and CsHCO3 during cyclic voltammetry. After correcting for the shape of the particle, there was less than 20% difference in the coverage of adsorbed CO on...
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Crystal Plane controlled selectivity of cu2o catalysts in propylene oxidation with molecular oxygen
Angewandte Chemie, 2014Co-Authors: Qing Hua, Zhiquan Jiang, Tian Cao, Xiaorong Pan, Liangfeng Luo, Weixin HuangAbstract:The selective oxidation of propylene with O2 to propylene oxide and acrolein is of great interest and importance. We report the Crystal-Plane-controlled selectivity of uniform capping-ligand-free Cu2 O octahedra, cubes, and rhombic dodecahedra in catalyzing propylene oxidation with O2 : Cu2 O octahedra exposing {111} Crystal Planes are most selective for acrolein; Cu2 O cubes exposing {100} Crystal Planes are most selective for CO2 ; Cu2 O rhombic dodecahedra exposing {110} Crystal Planes are most selective for propylene oxide. One-coordinated Cu on Cu2 O(111), three-coordinated O on Cu2 O(110), and two-coordinated O on Cu2 O(100) were identified as the catalytically active sites for the production of acrolein, propylene oxide, and CO2 , respectively. These results reveal that Crystal-Plane engineering of oxide catalysts could be a useful strategy for developing selective catalysts and for gaining fundamental understanding of complex heterogeneous catalytic reactions at the molecular level.
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Crystal Plane dependent surface reactivity and catalytic property of oxide catalysts studied with oxide nanoCrystal model catalysts
ChemInform, 2013Co-Authors: Weixin HuangAbstract:Oxides are widely used in heterogeneous catalysis, thus fundamental understanding of structure–activity relationships of oxide catalysts is of great importance for the improvement and design of efficient catalysts. Recently the synthesis of oxide nanoCrystals with uniform and well-defined structures has achieved great progress, and these oxide nanoCrystals consist of a novel type of model catalysts for oxide catalysts. Employing oxide nanoCrystal model catalysts, Crystal Plane-dependent surface reactivity and catalytic property of oxide catalysts have been successfully revealed. The recent progress is reviewed in this article and two systems are highlighted. One is cuprous oxide whose Crystal Planes affect the surface reactivity and catalytic property dominantly by Crystal Plane-dependent surface composition and structure; the other is ceria whose Crystal Planes affect the surface reactivity and catalytic property dominantly by Crystal Plane-dependent concentration and type of oxygen vacancy.
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Crystal Plane dependent surface reactivity and catalytic property of oxide catalysts studied with oxide nanoCrystal model catalysts
Topics in Catalysis, 2013Co-Authors: Weixin HuangAbstract:Oxides are widely used in heterogeneous catalysis, thus fundamental understanding of structure–activity relationships of oxide catalysts is of great importance for the improvement and design of efficient catalysts. Recently the synthesis of oxide nanoCrystals with uniform and well-defined structures has achieved great progress, and these oxide nanoCrystals consist of a novel type of model catalysts for oxide catalysts. Employing oxide nanoCrystal model catalysts, Crystal Plane-dependent surface reactivity and catalytic property of oxide catalysts have been successfully revealed. The recent progress is reviewed in this article and two systems are highlighted. One is cuprous oxide whose Crystal Planes affect the surface reactivity and catalytic property dominantly by Crystal Plane-dependent surface composition and structure; the other is ceria whose Crystal Planes affect the surface reactivity and catalytic property dominantly by Crystal Plane-dependent concentration and type of oxygen vacancy.
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Shape-dependent reducibility of cuprous oxide nanoCrystals
Journal of Physical Chemistry C, 2010Co-Authors: Huizhi Bao, Daili Shang, Zhiquan Jiang, Qing Hua, Yunsheng Ma, Jinlong Yang, Wenhua Zhang, Weixin HuangAbstract:In this paper the reducibility of octahedral and cubic Cu2O nanoCrystals that respectively expose the (111) and (100) Crystal Planes has been investigated both experimentally and theoretically. Reduced either by H2 or CO, the reduction temperature of octahedral Cu2O nanoCrystals is lower than that of cubic Cu2O nanoCrystals by more than 120 °C, which provides the unambiguous experimental results that the Cu2O(111) Crystal Plane is much more facile to be reduced than the Cu2O(100) Crystal Plane. The DFT calculation results reveal that the different reducibilities of octahedral and cubic Cu2O nanoCrystals arise from their different surface structures, in which the Cu2O(111) surface has coordination unsaturated Cu but the Cu2O(100) surface does not. The chemisorption and activation of CO and H2 are stronger on the Cu2O(111) surface than on the Cu2O(100) surface. These results provide the convincing evidence for the shape-dependent surface reactivity of oxide nanoCrystals.
Xinjian Feng - One of the best experts on this subject based on the ideXlab platform.
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1010 oriented multichannel zno nanowire arrays with enhanced optoelectronic device performance
Journal of the American Chemical Society, 2014Co-Authors: Xia Sheng, Jie Yang, Liping Chen, Kai Zhu, Xinjian FengAbstract:Crystallographic orientation and microstructure of metal oxide nanomaterials have great impact on their properties and applications. Here, we report [1010] oriented ZnO nanowire (NW) arrays with a multichannel mesostructure. The NW has a preferential growth of low energy (1010) Crystal Plane and exhibits 2–3 orders of magnitude faster electron transport rate than that in nanoparticle (NP) films. Furthermore, the surface area of the as-prepared NW arrays is about 5 times larger than that of conventional NW arrays with similar thickness. These lead to the highest power conversion efficiency of ZnO NW array-based sensitized solar cells. We anticipate that the unique Crystallographic orientation and mesostructure will endow ZnO NW arrays new properties and expand their application fields.
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vertically aligned single Crystal tio2 nanowire arrays grown directly on transparent conducting oxide coated glass synthesis details and applications
Nano Letters, 2008Co-Authors: Xinjian Feng, Karthik Shankar, Oomman K Varghese, Maggie Paulose, Thomas J Latempa, Craig A GrimesAbstract:Single-Crystal one-dimensional (1D) semiconductor architectures are important in materials-based applications requiring a large surface area, morphological control, and superior charge transport. Titania has widespread utility in applications including photocatalysis, photochromism, photovoltaics, and gas sensors. While considerable efforts have focused on the preparation of 1D TiO2, no methods have been available to grow Crystalline nanowire arrays directly onto transparent conducting oxide (TCO) substrates, greatly limiting the performance of TiO2 photoelectrochemical devices. Herein, we present a straightforward low temperature method to prepare single Crystal rutile TiO2 nanowire arrays up to 5 μm long on TCO glass via a non-polar solvent/hydrophilic substrate interfacial reaction under mild hydrothermal conditions. The as-prepared densely packed nanowires grow vertically oriented from the TCO glass substrate along the (110) Crystal Plane with a preferred (001) orientation. In a dye sensitized solar c...
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vertically aligned single Crystal tio2 nanowire arrays grown directly on transparent conducting oxide coated glass synthesis details and applications
Nano Letters, 2008Co-Authors: Xinjian Feng, Karthik Shankar, Oomman K Varghese, Maggie Paulose, Thomas J Latempa, Craig A GrimesAbstract:Single-Crystal one-dimensional (1D) semiconductor architectures are important in materials-based applications requiring a large surface area, morphological control, and superior charge transport. Titania has widespread utility in applications including photocatalysis, photochromism, photovoltaics, and gas sensors. While considerable efforts have focused on the preparation of 1D TiO2, no methods have been available to grow Crystalline nanowire arrays directly onto transparent conducting oxide (TCO) substrates, greatly limiting the performance of TiO2 photoelectrochemical devices. Herein, we present a straightforward low temperature method to prepare single Crystal rutile TiO2 nanowire arrays up to 5 microm long on TCO glass via a non-polar solvent/hydrophilic substrate interfacial reaction under mild hydrothermal conditions. The as-prepared densely packed nanowires grow vertically oriented from the TCO glass substrate along the (110) Crystal Plane with a preferred (001) orientation. In a dye sensitized solar cell, N719 dye, using TiO2 nanowire arrays 2-3 microm long we achieve an AM 1.5 photoconversion efficiency of 5.02%.
Craig A Grimes - One of the best experts on this subject based on the ideXlab platform.
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vertically aligned single Crystal tio2 nanowire arrays grown directly on transparent conducting oxide coated glass synthesis details and applications
Nano Letters, 2008Co-Authors: Xinjian Feng, Karthik Shankar, Oomman K Varghese, Maggie Paulose, Thomas J Latempa, Craig A GrimesAbstract:Single-Crystal one-dimensional (1D) semiconductor architectures are important in materials-based applications requiring a large surface area, morphological control, and superior charge transport. Titania has widespread utility in applications including photocatalysis, photochromism, photovoltaics, and gas sensors. While considerable efforts have focused on the preparation of 1D TiO2, no methods have been available to grow Crystalline nanowire arrays directly onto transparent conducting oxide (TCO) substrates, greatly limiting the performance of TiO2 photoelectrochemical devices. Herein, we present a straightforward low temperature method to prepare single Crystal rutile TiO2 nanowire arrays up to 5 μm long on TCO glass via a non-polar solvent/hydrophilic substrate interfacial reaction under mild hydrothermal conditions. The as-prepared densely packed nanowires grow vertically oriented from the TCO glass substrate along the (110) Crystal Plane with a preferred (001) orientation. In a dye sensitized solar c...
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vertically aligned single Crystal tio2 nanowire arrays grown directly on transparent conducting oxide coated glass synthesis details and applications
Nano Letters, 2008Co-Authors: Xinjian Feng, Karthik Shankar, Oomman K Varghese, Maggie Paulose, Thomas J Latempa, Craig A GrimesAbstract:Single-Crystal one-dimensional (1D) semiconductor architectures are important in materials-based applications requiring a large surface area, morphological control, and superior charge transport. Titania has widespread utility in applications including photocatalysis, photochromism, photovoltaics, and gas sensors. While considerable efforts have focused on the preparation of 1D TiO2, no methods have been available to grow Crystalline nanowire arrays directly onto transparent conducting oxide (TCO) substrates, greatly limiting the performance of TiO2 photoelectrochemical devices. Herein, we present a straightforward low temperature method to prepare single Crystal rutile TiO2 nanowire arrays up to 5 microm long on TCO glass via a non-polar solvent/hydrophilic substrate interfacial reaction under mild hydrothermal conditions. The as-prepared densely packed nanowires grow vertically oriented from the TCO glass substrate along the (110) Crystal Plane with a preferred (001) orientation. In a dye sensitized solar cell, N719 dye, using TiO2 nanowire arrays 2-3 microm long we achieve an AM 1.5 photoconversion efficiency of 5.02%.
Xiaojiang Yao - One of the best experts on this subject based on the ideXlab platform.
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effects of the morphology and Crystal Plane of tio2 on nh3 scr performance and k tolerance of v2o5 wo3 tio2 catalyst
Applied Catalysis A-general, 2021Co-Authors: Jun Cao, Li Chen, Weizao Liu, Keke Kang, Xu Qiao, Xiaojiang YaoAbstract:V2O5-WO3/TiO2 is the commercial NH3-SCR catalyst, the morphology and Crystal-Plane of its support can influence the denitration performance and K tolerance efficiently. TiO2 nano-rods (TiO2-NRs, mainly exposed the {100} facets) has larger BET surface area than those of TiO2 nano-octahedrons (TiO2-NOs, mainly exposed the {101} facets) and TiO2 nano-truncated octahedrons (TiO2-NTs, mainly exposed the {001} facets). The larger BET surface area was conducive to the dispersion of active species, thereby generating more active sites and enhancing the amount of V5+ ratio. Moreover, there was a stronger interaction between the active species (V2O5 and WO3) and TiO2-NRs support, which led to the increase of chemisorbed oxygen ratio and the improvement of surface acidity and redox ability. Furthermore, NH3-SCR reaction over V2O5-WO3/TiO2-NRs (i.e., VWTi-NRs) catalyst followed by both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms. While it only followed by an L-H mechanism over V2O5-WO3/TiO2- NOs (i.e., VWTi-NOs) and V2O5-WO3/TiO2-NTs (i.e., VWTi-NTs) catalysts.
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morphology and Crystal Plane effects of ceo2 on tio2 ceo2 catalysts during nh3 scr reaction
Industrial & Engineering Chemistry Research, 2018Co-Authors: Xiaojiang Yao, Li Chen, Jun Cao, Fumo Yang, Wei Tan, Lin DongAbstract:A series of supported TiO2/CeO2 catalysts were synthesized to investigate the morphology and Crystal-Plane effects of CeO2 on these TiO2/CeO2 catalysts for selective catalytic reduction by ammonia (NH3-SCR). The experiment results show that TiO2/CeO2-NC, TiO2/CeO2-NP, and TiO2/CeO2-NR catalysts present nanocubes (mainly exposed {100} facet), nanopolyhedrons (mainly exposed {111} and {100} facets), and nanorods (mainly exposed {110} and {100} facets), respectively. Furthermore, TiO2/CeO2-NR catalyst exhibits the best dispersion of TiO2 species, the most excellent reduction behavior and surface acidity, and the largest amount of Ce3+ ions and chemisorbed oxygen, which is due to the largest specific surface area and pore volume of CeO2-NR support, as well as the strongest interaction between the surface dispersed TiO2 species and the {110} facet of CeO2-NR support. All of them result in the best denitration performance of TiO2/CeO2-NR catalyst during NH3-SCR reaction.
Lin Dong - One of the best experts on this subject based on the ideXlab platform.
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morphology and Crystal Plane effects of ceo2 on tio2 ceo2 catalysts during nh3 scr reaction
Industrial & Engineering Chemistry Research, 2018Co-Authors: Xiaojiang Yao, Li Chen, Jun Cao, Fumo Yang, Wei Tan, Lin DongAbstract:A series of supported TiO2/CeO2 catalysts were synthesized to investigate the morphology and Crystal-Plane effects of CeO2 on these TiO2/CeO2 catalysts for selective catalytic reduction by ammonia (NH3-SCR). The experiment results show that TiO2/CeO2-NC, TiO2/CeO2-NP, and TiO2/CeO2-NR catalysts present nanocubes (mainly exposed {100} facet), nanopolyhedrons (mainly exposed {111} and {100} facets), and nanorods (mainly exposed {110} and {100} facets), respectively. Furthermore, TiO2/CeO2-NR catalyst exhibits the best dispersion of TiO2 species, the most excellent reduction behavior and surface acidity, and the largest amount of Ce3+ ions and chemisorbed oxygen, which is due to the largest specific surface area and pore volume of CeO2-NR support, as well as the strongest interaction between the surface dispersed TiO2 species and the {110} facet of CeO2-NR support. All of them result in the best denitration performance of TiO2/CeO2-NR catalyst during NH3-SCR reaction.
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morphology and Crystal Plane effects of nanoscale ceria on the activity of cuo ceo2 for no reduction by co
Chemcatchem, 2011Co-Authors: Lianjun Liu, Zhijian Yao, Yu Deng, Fei Gao, Bin Liu, Lin DongAbstract:The present work elucidated the morphology and Crystal-Plane effects of nanoscale ceria on the activity of CuO/CeO2 catalysts toward NO reduction. CeO2 Nanopolyhedra were enclosed by (111) and (100) Planes; the nanorods predominantly exposed (110) and (100) surfaces, and the nanocubes only showed the polar (100) Planes. Moreover, the strongest interaction was between CuO and CeO2 rods, followed by CuO/CeO2 polyhedra, and the CuO/CeO2 cubes showed the least interaction. Importantly, Cu2+ ions could be incorporated into the pore and surface lattices by occupying the vacant sites in the nanostructure CeO2 rods. Partial copper oxide species were segregated on the surface of CeO2 cubes with larger particle sizes. As a result, the site geometry and coordination environment of Cu2+ ions were different on the (111), (110), and (100) surfaces of CeO2. This surface structure effect in turn led to a higher surface reducibility, activity and N2 selectivity of CuO/CeO2 nanorods for NO reduction at low temperatures (below 250 °C); the polyhedra and cubes were less active.