The Experts below are selected from a list of 1248 Experts worldwide ranked by ideXlab platform
Joo, Sang Hoon - One of the best experts on this subject based on the ideXlab platform.
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Preferential Horizontal Growth of WS2 Nanosheet on Carbon Nanorod: An Highly Efficient Electrocatalyst for the Hydrogen Evolution Reaction
?????????????????????, 2016Co-Authors: Seo Bora, Kim, Jae Hyung, Kwak, Sang Kyu, Joo, Sang HoonAbstract:Desired material properties in layered transition metal dichalcogenides can be realized by understanding their growth behavior, which is predominantly affected by the growth mechanism and energetics. Particularly for electrocatalytic applications, where porous Carbons are predominantly used as conductive support, understanding their growth behavior on porous Carbon surfaces is of critical importance. In this work, we synthesized MS2 (M = Mo or W) nanoplates embedded on porous Carbon Nanorod arrays (MS2@OMCs) by limiting their growth space in nanoscale. We found that vertical growth is favored in MoS2 to generate multiply stacked MoS2 nanoplates, whereas the horizontal growth is preferred in WS2 to give rise to monolayer nanoplates. We theoretically explored the energetics of MS2 according to their growth orientation. The stacking energies for MoS2 were larger than those for WS2, confirming the experimental results. We applied WS2@OMCs as electrocatalysts for hydrogen evolution reaction (HER). WS2@OMCs exhibit high catalytic activity with a low overpotential of 179 mV vs. RHE (at 10 mA cm-2) and low Tafel slope of 63 mV sec-1
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Preferential Horizontal Growth of WS2 Nanoplate on Porous Carbon: A Highly Efficient Electrocatalyst for the Hydrogen Evolution Reaction
'The Electrochemical Society', 2016Co-Authors: Seo Bora, Kim, Jae Hyung, Kwak, Sang Kyu, Jung, Gwan Yeong, Joo, Sang HoonAbstract:Two-dimensional layered transition metal dichalcogenides (2D TMDs) have been of tremendous recent interests. Understanding their growth behavior on specific substrate or support can provide critical insights for designing the TMDs with desirable structure and functionality for targeted applications. Particularly for the electrocatalytic hydrogen evolution reaction (HER), where porous Carbons are predominantly used as conductive supports, revealing the growth behavior of TMDs on porous Carbon materials can suggest rational design concept for the TMD-based HER catalysts. With an aim to investigate the growth orientation on porous Carbon support, we synthesized MS2 (M = W or Mo) nanoplates embedded on porous Carbon Nanorod arrays by limiting their growth space at the nanoscale. We found that the horizontal growth is preferred in WS2 giving rise to monolayer nanoplates, which is contrast to the growth of MoS2 that favors vertical stacking to generate multilayer structure. Density functional theory calculations of adhesion energy of TMDs on porous Carbons and their stacking energies revealed that WS2 favor the basal plane bonding with Carbon support and horizontal growth, wheareas the edge bonding and vertical growth is favored for MoS2, supporting experimental results. The orientation-controlled WS2 monolayer NPs embedded in mesoporous Carbon exhibited highly efficient electrocatalytic activity for the HER with a low overpotential of 179 mV (vs RHE) at ‒10 mA cm-2 and low Tafel slope of 63 mV sec-1
Xin Wang - One of the best experts on this subject based on the ideXlab platform.
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construction of n doped Carbon mose2 core branch nanostructure via simultaneous formation of core and branch for high performance lithium ion batteries
Electrochimica Acta, 2017Co-Authors: Jiayu Wang, Changqing Peng, Lili Zhang, Xianmin Zhao, Junwu Zhu, Xin WangAbstract:Abstract Here, we report a one-step simultaneous-construction approach to synthesize N-doped Carbon@MoSe 2 core/branch nanostructures by heating a mixture of MoO 3 /PANI hybrids and Se powders in argon atmosphere, without requiring a cumbersome multi-step process or highly toxic reducing agents. It is found that in the construction process, PANI played a crucial role in the reduction of MoO 3 and Se to form MoSe 2 nanosheet branches, while PANI itself was decomposed and Carbonized into N-doped Carbon Nanorod cores. Interestingly, the coexistence of 1D and 2D nanostructures in the N-doped Carbon@MoSe 2 core/branch system leads to excellent lithium storage performance, including a large discharging capacity of 1275 mA h g −1 , a high reversible lithium extraction capacity of 928 mA h g −1 and a coulombic efficiency of 72.8%. After 100 cycles, the NDC@MS electrode still delivers a reversible capacity of 906 mA h g −1 with a capacity retention ratio of 97.6%. The superior electrochemical properties can be attributed to the unique core/branch nanostructure of NDC@MS and the synergistic effect between the N-doped Carbon Nanorod cores and MoSe 2 nanosheet branches.
Seo Bora - One of the best experts on this subject based on the ideXlab platform.
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Preferential Horizontal Growth of WS2 Nanosheet on Carbon Nanorod: An Highly Efficient Electrocatalyst for the Hydrogen Evolution Reaction
?????????????????????, 2016Co-Authors: Seo Bora, Kim, Jae Hyung, Kwak, Sang Kyu, Joo, Sang HoonAbstract:Desired material properties in layered transition metal dichalcogenides can be realized by understanding their growth behavior, which is predominantly affected by the growth mechanism and energetics. Particularly for electrocatalytic applications, where porous Carbons are predominantly used as conductive support, understanding their growth behavior on porous Carbon surfaces is of critical importance. In this work, we synthesized MS2 (M = Mo or W) nanoplates embedded on porous Carbon Nanorod arrays (MS2@OMCs) by limiting their growth space in nanoscale. We found that vertical growth is favored in MoS2 to generate multiply stacked MoS2 nanoplates, whereas the horizontal growth is preferred in WS2 to give rise to monolayer nanoplates. We theoretically explored the energetics of MS2 according to their growth orientation. The stacking energies for MoS2 were larger than those for WS2, confirming the experimental results. We applied WS2@OMCs as electrocatalysts for hydrogen evolution reaction (HER). WS2@OMCs exhibit high catalytic activity with a low overpotential of 179 mV vs. RHE (at 10 mA cm-2) and low Tafel slope of 63 mV sec-1
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Preferential Horizontal Growth of WS2 Nanoplate on Porous Carbon: A Highly Efficient Electrocatalyst for the Hydrogen Evolution Reaction
'The Electrochemical Society', 2016Co-Authors: Seo Bora, Kim, Jae Hyung, Kwak, Sang Kyu, Jung, Gwan Yeong, Joo, Sang HoonAbstract:Two-dimensional layered transition metal dichalcogenides (2D TMDs) have been of tremendous recent interests. Understanding their growth behavior on specific substrate or support can provide critical insights for designing the TMDs with desirable structure and functionality for targeted applications. Particularly for the electrocatalytic hydrogen evolution reaction (HER), where porous Carbons are predominantly used as conductive supports, revealing the growth behavior of TMDs on porous Carbon materials can suggest rational design concept for the TMD-based HER catalysts. With an aim to investigate the growth orientation on porous Carbon support, we synthesized MS2 (M = W or Mo) nanoplates embedded on porous Carbon Nanorod arrays by limiting their growth space at the nanoscale. We found that the horizontal growth is preferred in WS2 giving rise to monolayer nanoplates, which is contrast to the growth of MoS2 that favors vertical stacking to generate multilayer structure. Density functional theory calculations of adhesion energy of TMDs on porous Carbons and their stacking energies revealed that WS2 favor the basal plane bonding with Carbon support and horizontal growth, wheareas the edge bonding and vertical growth is favored for MoS2, supporting experimental results. The orientation-controlled WS2 monolayer NPs embedded in mesoporous Carbon exhibited highly efficient electrocatalytic activity for the HER with a low overpotential of 179 mV (vs RHE) at ‒10 mA cm-2 and low Tafel slope of 63 mV sec-1
Jiayu Wang - One of the best experts on this subject based on the ideXlab platform.
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construction of n doped Carbon mose2 core branch nanostructure via simultaneous formation of core and branch for high performance lithium ion batteries
Electrochimica Acta, 2017Co-Authors: Jiayu Wang, Changqing Peng, Lili Zhang, Xianmin Zhao, Junwu Zhu, Xin WangAbstract:Abstract Here, we report a one-step simultaneous-construction approach to synthesize N-doped Carbon@MoSe 2 core/branch nanostructures by heating a mixture of MoO 3 /PANI hybrids and Se powders in argon atmosphere, without requiring a cumbersome multi-step process or highly toxic reducing agents. It is found that in the construction process, PANI played a crucial role in the reduction of MoO 3 and Se to form MoSe 2 nanosheet branches, while PANI itself was decomposed and Carbonized into N-doped Carbon Nanorod cores. Interestingly, the coexistence of 1D and 2D nanostructures in the N-doped Carbon@MoSe 2 core/branch system leads to excellent lithium storage performance, including a large discharging capacity of 1275 mA h g −1 , a high reversible lithium extraction capacity of 928 mA h g −1 and a coulombic efficiency of 72.8%. After 100 cycles, the NDC@MS electrode still delivers a reversible capacity of 906 mA h g −1 with a capacity retention ratio of 97.6%. The superior electrochemical properties can be attributed to the unique core/branch nanostructure of NDC@MS and the synergistic effect between the N-doped Carbon Nanorod cores and MoSe 2 nanosheet branches.
Shuai Wang - One of the best experts on this subject based on the ideXlab platform.
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nanostructured co ni based compounds coated on a highly conductive three dimensional hollow Carbon Nanorod array hcna scaffold for high performance pseudocapacitors
ACS Applied Materials & Interfaces, 2014Co-Authors: Lian Wan, Junwu Xiao, Fei Xiao, Shuai WangAbstract:The electrochemical performance of the pseudocapacitive materials is seriously limited by poor electron and ions transport. Herein, an advanced integrated electrode has been designed by growing the pseudocapacitive materials, including CoxNi1–x(OH)2, CoxNi1–xO, and (CoxNi1–x)9S8, on a three-dimensional hollow Carbon Nanorod arrays (HCNA) scaffold. The HCNA scaffold not only can provide large surface area for increasing the mass loading of the pseudocapacitive materials, but also is with good electrical conductivity and hollow structure for facilitating fast electron and electrolyte ions transport, and thus improve the electrochemical performance. Particularly, in comparison with CoxNi1–x(OH)2 and CoxNi1–xO nanosheets, (CoxNi1–x)9S8 nanosheets on the HCNA scaffold exhibit better electrochemical performance. The discharge areal capacitance of the (CoxNi1–x)9S8/HCNA electrode can be achieved to 1.32 F cm–2 at 1 mA cm–2, ∼1.5 times as that of the CoxNi1–x(OH)2/HCNA electrode. The rate capability performance i...