Topology conversion of 1T MoS_(2) to S-doped 2H-MoTe_(2) nanosheets with Te vacancies for enhanced electrocatalytic hydrogen evolution  

拓扑转化1T MoS2为硫掺杂碲空位的MoTe2纳米片及其增强电催化氢析出

作　　者：Yaqian Wang Yongli Shen Xiong Xiao Linxiu Dai Shuang Yao Changhua An 王雅倩;申勇立;肖雄;代林秀;姚爽;安长华(Life and Health Institute,Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion,School of Chemistry and Chemical Engineering,Tianjin University of Technology,Tianjin 300384,China;Tianjin Key Laboratory of Advanced Functional Porous Materials,Institute for New Energy Materials&Low-Carbon Technologies,School of Materials Science and Engineering,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]Life and Health Institute,Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion,School of Chemistry and Chemical Engineering,Tianjin University of Technology,Tianjin 300384,China [2]Tianjin Key Laboratory of Advanced Functional Porous Materials,Institute for New Energy Materials&Low-Carbon Technologies,School of Materials Science and Engineering,Tianjin University of Technology,Tianjin 300384,China

出　　处：《Science China Materials》2021年第9期2202-2211,共10页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(21771137)。

摘　　要：Metastable 1T’MoTe_(2) has attracted much attention as a cost-effective electrocatalyst for hydrogen evolution reaction(HER)in recent years.However,few studies were done over common stable 2 H phase because it often exhibits inferior performance.Herein,stable 2H MoTe_(2) with S-doped Te vacancies has been synthesized by one-step telluride conversion of 1T MoS_(2) at 700℃under Ar/H_(2) atmosphere.It is demonstrated that the synergistic effect of S-doping and Te vacancies changes the electronic structures of the catalyst.Density functional theory(DFT)studies show that plentiful electrons accumulate on the surface S atoms in S-doped Te vacancies of 2H MoTe_(2) catalyst,which may be as active sites to promote HER.Moreover,the as-synthesized catalyst can be directly used as working electrode,and realizes current density of 100 mA cm^(-2) at overpotential of 217 mV with Tafel slope of 94 mV dec^(-1).This work stimulates intensive studies on the activation of inert phase of other nanocatalysts towards various reactions.本文在Ar/H_(2)气氛中通过原位转化1T MoS_(2)法合成出一种负载型MoTe_(2)纳米片.其表征结果说明,反应过程中硫引入到MoTe_(2)纳米片,同时产生了碲空位,使得电化学比表面积增大,活性位点增多;硫掺杂和碲空位的协同作用促进了H^(*)的吸附及H_(2)的析出.氮掺杂碳负载的硫掺杂含碲空位的MoTe_(2)可直接用作工作电极,在217 mV过电位下实现了100 mA cm^(-2)的电流密度,塔菲尔斜率为94 mV dec^(-1).催化剂在酸性电解质中表现出优异的稳定性,优于多数已报道的MoTe_(2)电催化剂.该工作为优化其他半导体惰性纳米催化剂提供了思路.

关 键 词：MoTe_(2) DEFECT ELECTROCATALYSIS hydrogen evolution 

分 类 号：TQ116.2[化学工程—无机化工] TQ426[一般工业技术—材料科学与工程] TB383.1