Sulfur-deficient CoNi_(2)S_(4)nanoparticles-anchored porous carbon nanofibers as bifunctional electrocatalyst for overall water splitting

查看全文 作　　者：Gaohui [1,2]Du;Yi [2]Fan;Lina [2]Jia;Yunting [2]Wang;Yawen [2]Hao;Wenqi [2]Zhao;Qingmei [2]Su;Bingshe [1,2]Xu 机构地区：[1]Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering,Taiyuan 030000,China;[2]Materials Institute of Atomic and Molecular Science,Shaanxi University of Science and Technology,Xi’an 710021,China 出　　处：《Frontiers of Chemical Science and Engineering》索引2023年第17卷第11期,共11页 基　　金：the financial supports from Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(Grant No.2022SX-TD003);the National Natural Science Foundation of China(Grant Nos.U2032131 and 52102048). 摘　　要：Water electrolysis technology is considered to be one of the most promising means to produce hydrogen.Herein,aiming at the problems of high overpotential and slow kinetics in water splitting,N-doped porous carbon nanofibers-coupled CoNi_(2)S_(4)nanoparticles are prepared as bifunctional electrocatalyst.In the strategy,NaCl is used as the template to prepare porous carbon nanofibers with a large surface area,and sulfur vacancies are created to modulate the electronic structure of CoNi_(2)S_(4).Electron spin resonance confirms the formation of abundant sulfur vacancies,which largely reduce the bandgap of CoNi_(2)S_(4)from 1.68 to 0.52 eV.The narrowed bandgap is conducive to the migration of valence electrons and decreases the charge transfer resistance for electrocatalytic reaction.Moreover,the uniform distribution of CoNi_(2)S_(4)nanoparticles on carbon nanofibers can prevent the aggregation and facilitate the exposure of electrochemical active sites.Therefore,the composite catalyst exhibits low overpotentials of 340 mV@100 mA·cm^(-2)for oxygen evolution reaction and 380 mV@100 mA·cm^(-2)for hydrogen evolution reaction.The assembled electrolyzer requires 1.64 V to achieve 10 mA·cm^(-2)for overall water-splitting with good long-term stability.The excellent performance results from the synergistic effect of porous structures,sulfur deficiency,nitrogen doping,and the well-dispersed active component. 关 键 词：NANOPARTICLE sulfur vacancy porous carbon nanofiber transition metal sulfides electrolysis