Hydrothermal Synthesis And Electrochemical Properties Of Two Dimensional Transition Metal Sulfide/Graphene Nanocomposites

In the past decade,the rapid development of two-dimensional nanometer materials provides a new opportunity for the development of catalysts with high stability,activity and selectivity.Because of its unique structure,two-dimensional nanometer materials have been widely used in photoelectric catalysis to solve the environmental and energy problems encountered in green catalysis.In the process of research,it has been proved that the composite catalyst of two-dimensional nanometer materials plays a great role in the promotion of catalytic performance.However,the lack of research on the synthesis technology and catalyst mechanism inhibits the development of hydrogen evolution catalysis in fuel cells.In order to improve the catalytic activity,stability and selectivity of the catalyst,a novel composite nanometer catalyst was prepared by hydrothermal synthesis with graphene supported two-dimensional transition metal sulfides.In the paper,we combine the controlled synthesis,characterization and theoretical simulation.At the same time,We use the catalytic activity and performance characterization of the catalyst in the catalytic process to study the catalytic mechanism.With the support of Graphene?GO?,two dimensional transition metal sulfide was synthesized by hydrothermal synthesis to improve the catalytic activity,stability and selectivity of the catalyst.The phase structure and properties of different products were systematically analyzed by ray diffractometer,scanning electron microscope,transmission electron microscope and electrochemical workstation.At the same time,the catalytic mechanism was studied through the catalytic activity and performance characterization of the catalyst during the catalytic process.We used WCl₆,C₂H₅NS and graphene to prepared WS₂/RGO by hydrothermal method oxide.The study shows that the large area agglomeration will occur with the increase of the use of graphene?GO?and the catalytic activity will lost.By optimizing the process parameters,it was found that the 12wt%RGO and two tungsten sulfide were good and the layered structure was obvious.Transmission electron microscopy and X ray diffractometer analysis show that a lot of stacking faults,dislocations and vacancies are in the WS₂/RGO nanostructures which have high specific surface area and porosity.The results of electrochemical performance test show that the WS₂/RGO nanomaterial has a certain catalytic effect.However,the catalytic effect is not ideal and its tafe slope is only 62mV/dec.We also analyze the effect of platinum on catalytic effect.The experiment shows that platinum greatly enhance the efficiency of catalyst and the 10wt%platinum can reach the effect of commercial Pt/C catalyst,which is mainly attributed to the excellent conductivity.At the same time,the-two-dimensional structure also keeps the uniform dispersion of Pt nanoparticles and significantly improve the performance of cathode.The morphology and catalytic properties of hydrogen evolution of different proportions of WS₂/SnS₂ were studied using the carrier of graphene.In the experiment,the WS₂/SnS₂/GO nanocomposites are synthesized by hydrothermal method in one step.We find that the two-dimensional layered structure reduces the agglomeration of single material.However,the different quality of WS₂ and SnS₂ has different effects to the performance of cathode.When the ratio of WS2 and SnS2 was 2:1,the structure have a lot of active sites.The synergistic catalysis and the electrocatalysis are the most obvious.And the composite has excellent conductivity,quickening the path of the electron in the loop,and remarkable catalytic performance.