Preparation Of Tungsten Sulfide Composite Material And Study On Its Electrocatalytic Hydrogen Evolution Performance

Hydrogen manufacture by electrolysis of water is a valid,steady,green,low-carbon and low-cost hydrogen manufacture.Transition metal sulfides are confessedly take advantage in the principal of hydrogen fabrication by electrolysis of water owing to their favorable catalytic doings.In terms of transition metal sulfides,tungsten disulfide（WS₂）has fascinated the heed of scholares.Yet,the conventional single WS₂is restricted in its submissions in the scopes of electrochemical hydrogen evolvement owing to its beneath conductivity and few dynamic speckes.The introduction of highly conductive materials and the design of structures with rich active sites are the key research directions for improving the performance of hydrogen evolution of catalysts in the future.In this paper,in view of the way of carbon material ethylene diamine introduced,WS₂/C and Pt-WS₂/C composite material were prepared by high temperature vulcanization,respectively.The structural composition of composite materials was analyzed by various ways of characterization.Meanwhile,the electrochemical performance of production was systematically researched.The specific research contents are as follows:（1）Using WO₃/EDA as precursor and thiourea as sulfur source,sheet-structured WS₂/C composite was prepared by direct vulcanization at high temperature.The structural composition and morphology were studied.Besides,the effect of amount of ethylenediamine on structure and performance of carbon materials were discussed.By means of the electrochemical hydrogen evolution test of the WS₂/C composite,the results showed that WS₂/C-67.5 composite material had the best performance.When the current density was 10 m A/cm~2,the corresponding overpotential was 163 m V and the Tafel slope was 94 m V/dec.This was attributed to the fact that the sheet-structured edge of WS₂/C composites provided abundant active sites for hydrogen evolution in the electrochemical hydrogen evolution reaction.At the same time,owing to introduction of carbon material,the conductivity of the composite materials was improved,and WS₂/C composite material showed good performance for electrochemical hydrogen evolution.（2）Using H₂WO₄/EDA as precursor and thiourea as sulfur source,the sheet-structured WS₂/C composites were prepared by direct vulcanization at high temperature,and then the Pt-WS₂/C composite was synthesized by the in-situ hydrothermal method.The structural composition and morphology were studied.Also,the effects of different curing temperatures on the structure and performance were discussed.The results of the electrochemical hydrogen evolution test of the Pt-WS₂/C component composite demonstrated that the performance of Pt-WS₂/C-700 composites was the best when the curing temperature was 700℃.When the current density was 10 m A/cm~2,the corresponding overpotential was 147 m V and the Tafel slope is 94 m V/dec in 0.5 M H₂SO₄electrolyte.This is mainly attributed to the abundant hydrogen evolution active sites were provided by the edge of the sheet-structured Pt-WS₂/C-700 composites during the electrochemical hydrogen evolution reaction process.Meanwhile,the agglomeration between WS₂layers was hindered by carbon materials,so more hydrogen evolution active sites were present at the edge of the structure of the composites,and the electrochemical hydrogen evolution performance was improved.