Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a nove...Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a novel urchin-like NiCo2S4@mesocarbon microbead(NCS@MCMB) composite with a core–shell structure was prepared by a facile two-step hydrothermal method.The highly conductive MCMBs offered abundant adsorption sites for the growth of NCS nanoneedles,which allowed each nanoneedle to fully unfold without aggregation,resulting in improved NCS utilization and efficient electron/ion transferin the electrolyte.When applied as an electrode material for supercapacitors,the composite exhibited a maximum specific capacitance of 936 Fg-1 at 1 Ag-1 and a capacitance retention of 94% after 3000 cycles at 5 Ag-1,because of the synergistic effect of MCMB and NCS.Moreover,we fabricated an asymmetric supercapacitor based on the NCS@MCMB composite,which exhibited enlarged voltage windows and could power a light-emitting diode device for several minutes,further demonstrating the exceptional electrochemical performance of the NCS@MCMB composite.展开更多
Oil-soluble bimetallic Ni-Mo sulfide nanoparticles（NiMoS） with narrow size distribution were successfully synthesized through a composite-surfactants-assisted-solvothermal process.The surface functionality and lipop...Oil-soluble bimetallic Ni-Mo sulfide nanoparticles（NiMoS） with narrow size distribution were successfully synthesized through a composite-surfactants-assisted-solvothermal process.The surface functionality and lipophilicity of the Ni-Mo sulfides were shown by transmission electronic microscopy,Fourier transform infrared and ultraviolet spectroscopy.The as-prepared Ni-Mo sulfides supported on activated carbon（NiMoS/AC） exhibited enhanced catalytic activity towards naphthalene hydrogenation instead of cracking.For comparison,CoMoS/AC and MoS2/AC catalysts were also prepared through similar procedures,and it was found that their catalytic performance decreased in the order of NiMoS/AC〉CoMoS/AC〉MoS2/AC.Furthermore,the activity of the bimetallic NiMoS nanocatalyst can be effectively tuned via variation of the atomic ratio of Ni/（Ni＋Mo）.展开更多
近年来,随着柔性电子的快速发展,制造柔性、微型、大面积和低成本的储能器件得到了极大的关注。以六水硝酸镍/钴为原料、硫脲为硫化剂、引入热解g-CN,通过一步溶剂热制备NiCo_(2)S_(4)/g-CN纳米复合材料。采用掩膜版将调配的NiCo_(2)S_(...近年来,随着柔性电子的快速发展,制造柔性、微型、大面积和低成本的储能器件得到了极大的关注。以六水硝酸镍/钴为原料、硫脲为硫化剂、引入热解g-CN,通过一步溶剂热制备NiCo_(2)S_(4)/g-CN纳米复合材料。采用掩膜版将调配的NiCo_(2)S_(4)/g-CN油墨印刷在柔性聚对苯二甲酸乙二醇酯基底形成叉指结构电极,继而涂覆凝胶电解质组装成柔性叉指型超级电容器。结构和电化学性能研究表明:NiCo_(2)S_(4)纳米晶分布生长在g-CN纳米片层表面,引入的g-CN起到增强NiCo_(2)S_(4)充放电过程中的电荷传输及容纳其体积膨胀的作用,复合材料电极在10 m A/cm^(2)的电流密度下面积比电容为9.1 F/cm^(2)。组装的叉指电容器可在–0.2~0.6 V的电压下工作,并且在高至500 m V/s的扫描速率下保持稳定,表明器件良好的倍率性能。在20 m V/s的扫描速率下,器件的面积比电容可达5.7 m F/cm^(2),当功率密度为17.5 m W/cm~3时,器件的能量密度为0.56 m W·h/cm^(3)。展开更多
The electrocatalytic activity for hydrogen evolution reaction(HER)is strongly correlated with active edge sites and resulting efficient charge transport capability.Here,we presented a facile two-step method to synthes...The electrocatalytic activity for hydrogen evolution reaction(HER)is strongly correlated with active edge sites and resulting efficient charge transport capability.Here,we presented a facile two-step method to synthesize 3 D hierarchical NiS2/MoS2 composite nanostructures on a carbon fiber paper(CFP)skeleton.The nanostructures distributed on CFP uniformly and composed of 2 D nanosheets,which would provide plenty of active edge sites and increase the HER activity.Electrochemical measurement suggests that the prepared NiS2/MoS2 exhibit great HER activity including a low overpotential of 102 m V,a small Tafel slope of 67 m V/dec,and a high double-layer capacity of 53.7 m F/cm2 in 1 M KOH aqueous solution.In addition,the HER activity is almost unchanged after galvanostatic technique with applied current densities of10 m A/cm2 for 20 h.展开更多
基金jointly supported by the National Natural Science Foundations of China(No.51572246)the Fundamental Research Funds for the Central Universities(Nos.2652017401 and 2652015425)
文摘Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a novel urchin-like NiCo2S4@mesocarbon microbead(NCS@MCMB) composite with a core–shell structure was prepared by a facile two-step hydrothermal method.The highly conductive MCMBs offered abundant adsorption sites for the growth of NCS nanoneedles,which allowed each nanoneedle to fully unfold without aggregation,resulting in improved NCS utilization and efficient electron/ion transferin the electrolyte.When applied as an electrode material for supercapacitors,the composite exhibited a maximum specific capacitance of 936 Fg-1 at 1 Ag-1 and a capacitance retention of 94% after 3000 cycles at 5 Ag-1,because of the synergistic effect of MCMB and NCS.Moreover,we fabricated an asymmetric supercapacitor based on the NCS@MCMB composite,which exhibited enlarged voltage windows and could power a light-emitting diode device for several minutes,further demonstrating the exceptional electrochemical performance of the NCS@MCMB composite.
基金financially supported by Shandong Provincial Natural Science Foundation (ZR2011BQ020)the Fundamental Research Funds for the Central Universities (13CX05011A)
文摘Oil-soluble bimetallic Ni-Mo sulfide nanoparticles（NiMoS） with narrow size distribution were successfully synthesized through a composite-surfactants-assisted-solvothermal process.The surface functionality and lipophilicity of the Ni-Mo sulfides were shown by transmission electronic microscopy,Fourier transform infrared and ultraviolet spectroscopy.The as-prepared Ni-Mo sulfides supported on activated carbon（NiMoS/AC） exhibited enhanced catalytic activity towards naphthalene hydrogenation instead of cracking.For comparison,CoMoS/AC and MoS2/AC catalysts were also prepared through similar procedures,and it was found that their catalytic performance decreased in the order of NiMoS/AC〉CoMoS/AC〉MoS2/AC.Furthermore,the activity of the bimetallic NiMoS nanocatalyst can be effectively tuned via variation of the atomic ratio of Ni/（Ni＋Mo）.
文摘近年来,随着柔性电子的快速发展,制造柔性、微型、大面积和低成本的储能器件得到了极大的关注。以六水硝酸镍/钴为原料、硫脲为硫化剂、引入热解g-CN,通过一步溶剂热制备NiCo_(2)S_(4)/g-CN纳米复合材料。采用掩膜版将调配的NiCo_(2)S_(4)/g-CN油墨印刷在柔性聚对苯二甲酸乙二醇酯基底形成叉指结构电极,继而涂覆凝胶电解质组装成柔性叉指型超级电容器。结构和电化学性能研究表明:NiCo_(2)S_(4)纳米晶分布生长在g-CN纳米片层表面,引入的g-CN起到增强NiCo_(2)S_(4)充放电过程中的电荷传输及容纳其体积膨胀的作用,复合材料电极在10 m A/cm^(2)的电流密度下面积比电容为9.1 F/cm^(2)。组装的叉指电容器可在–0.2~0.6 V的电压下工作,并且在高至500 m V/s的扫描速率下保持稳定,表明器件良好的倍率性能。在20 m V/s的扫描速率下,器件的面积比电容可达5.7 m F/cm^(2),当功率密度为17.5 m W/cm~3时,器件的能量密度为0.56 m W·h/cm^(3)。
基金financially supported by Key Research and Development Project of Hainan Province(No.ZDYF2018106)National Natural Science Foundation of China(Nos.51762012,51461014,and 51862006)Key Laboratory Open Project Fund of Hainan University(2018008).
文摘The electrocatalytic activity for hydrogen evolution reaction(HER)is strongly correlated with active edge sites and resulting efficient charge transport capability.Here,we presented a facile two-step method to synthesize 3 D hierarchical NiS2/MoS2 composite nanostructures on a carbon fiber paper(CFP)skeleton.The nanostructures distributed on CFP uniformly and composed of 2 D nanosheets,which would provide plenty of active edge sites and increase the HER activity.Electrochemical measurement suggests that the prepared NiS2/MoS2 exhibit great HER activity including a low overpotential of 102 m V,a small Tafel slope of 67 m V/dec,and a high double-layer capacity of 53.7 m F/cm2 in 1 M KOH aqueous solution.In addition,the HER activity is almost unchanged after galvanostatic technique with applied current densities of10 m A/cm2 for 20 h.
基金financially supported by the National Natural Science Foundation of China(51973079)the Science and Technology Development Plan of Jilin Province,China(20220402008GH)。
文摘设计分层异质结构作为一种经济且高效的催化剂,以实现水分解的电子和界面工程,是能源存储与转化中的一个有意义的决策.在这项工作中,通过静电纺丝-碳化-电沉积的策略,制备了负载在嵌入Co纳米颗粒的碳纤维上的非晶态NiFeS纳米片(Co-C/NiFeS纳米纤维)催化剂.该催化剂具有优异的析氧反应(OER)活性,在1 mol L^(-1)KOH溶液中,在10 mA cm^(-2)下的过电位为233 mV,Tafel斜率为53.1 mV dec^(-1),同时还具有良好的析氢反应活性.此外,由Co-C/NiFeS纳米纤维作为阳极,商用Pt/C作为阴极构建的碱性Pt/C‖Co-C/NiFeS电解槽在10 mA cm^(-2)下实现1.48 V的低电池电压,优于基准Pt/C‖RuO_(2)电解槽和许多其他报道的电解槽.作为双功能电催化剂,Co-C/NiFeS‖Co-C/NiFeS自身组装的电解槽表现出70小时的长期稳定性,显著优于Pt/C‖RuO_(2)电解槽.该催化剂显著的OER性能得益于Co-C纳米纤维核与非晶NiFeS纳米片鞘组成的明显分层异质结构以及生成的高导电碳纤维基底,这些结构特征赋予该材料丰富的暴露活性位点、良好的导电性和坚固的结构稳定性.因此,这项工作提出了一种简单且有效的方法来制备具有优异电催化性能的非贵金属基催化剂,以用于实际的能量转换和存储.
