Preparation And Electrochemical Properties Of WS₂ Composites For Hydrogen Evolution Reduction

The preparation of electrochemical hydrogen evolution catalytic materials with high catalytic performance and high stability has been the focus of researchers.As a typical transition metal sulfide,WS₂has attracted much attention because of its unique layered structure.However,pure phase WS₂cannot be widely used due to its low catalytic performance and poor conductivity.In this paper,flake WS₂/WP/C composites and porous WS₂/C composites were synthesized respectively by chemical vapor deposition.The specific research content is as follows:?1?Using H₂W₂O₇/DDA as the precursor,thiourea as the sulfur source,and diammonium hydrogen phosphate as the phosphorus source,flake WS₂/WP/C composites were prepared by chemical vapor deposition.The flake structure of WS₂/WP/C composites can provide more structural edges and active sites.At the same time,the interface formed between WS₂and WP can effectively increase the electron density of the active sites and electron transfer capacity,thereby improving the electrochemical hydrogen evolution activity of the composites.The results of electrochemical hydrogen evolution tests show that the flake WS₂/WP/C composites need only an overpotential of 115 m V and a Tafel slope of 98 m V/dec at a current density of 10 m A/cm²,indicating that the flake WS₂/WP/C composites have high electrochemical hydrogen evolution activity.?2?Using H₂WO₄/DDA as the precursor,thiourea as the sulfur source.After homogeneous mixing,mixture was calcined at high temperature and then etched with a strong alkaline solution to obtain porous WS₂/C composites,so that the composites have more structural edges and active sites.The results of electrochemical hydrogen evolution show that the porous WS₂/C composites need an overpotential of 91 m V and a Tafel slope of 67 m V/dec at a current density of 10 m A/cm²,which indicates that the porous WS₂/C composites have good electrochemical hydrogen evolution activity.