| The excessive consumption of fossil energy has made human society’s demand for alternative energy sources more intense.Photocatalytic hydrogen evolution technology can effectively convert solar energy into hydrogen with high energy density,so photocatalytic hydrogen evolution is considered to be one of the effective ways to solve the energy crisis.Among them,the catalyst is the most important part to drive the photocatalytic hydrogen evolution.The cadmium sulfide and molybdenum disulfide composite materials have been widely studied because of their good performance beyond precious metal catalysts.In this paper,a series of experimental studies were carried out on precursors prepared from cadmium sulfide/molybdenum disulfide(CdS/MoS2)photocatalysts,and different sources of cadmium were investigated,including CdCl2,Cd(AC)2,Cd(NO3)2,CdSO4 And the influence of different sulfur sources,including thiourea and thioacetamide on the performance of photocatalyst.The specific research content is as follows:Four different cadmium sources and thiourea were used to successfully synthesize CdS/MoS2 composite materials by one-step hydrothermal method.A systematic characterization method was used to conduct a comprehensive analysis of the four samples,and the photocatalytic performance was evaluated by the amount of hydrogen evolution per unit time under light conditions.The experimental results show that the CdS/MoS2 photocatalyst synthesized by Cd(AC)2 has the strongest photocatalytic hydrogen evolution ability:19.34 mmol·g-1·h-1,which was 3.41,39.46 and 2.01 times more than those synthesized by CdCl2,Cd(NO3)2,and CdSO4,respectively.This is due to its larger specific surface area,more negative Zeta potential,better suppression of photogenerated carrier recombination,and the strongest visible light absorption.Secondly,the photocatalyst synthesized from Cd(NO3)2 has almost no load on CdS due to the oxidizing property of nitrate,resulting in the worst photocatalytic efficiency.By comparing its XRD spectrum and TEM image,it is proved that MoS2 supported on the(002)crystal plane of CdS can improve the photocatalytic efficiency.The CdS/MoS2 composite materials were synthesized from the four cadmium sources and thioacetamide using the same synthesis method,and their physical and chemical properties were comprehensively studied through various characterization methods.Compared with the composite materials synthesized by thiourea as a sulfur source,it is found that thiourea is the most suitable sulfur source for the synthesis of CdS/MoS2.Analysis of the XRD spectrum shows that the peaks of the(002)crystal planes of CdS in the four samples are weak,which further proves that the loading of MoS2 on the CdS(002)crystal plane can improve the photocatalytic efficiency.The results of its photocatalytic hydrogen evolution experiments show that thioacetamide as a sulfur source has poor photocatalytic hydrogen evolution performance of the four composite materials,and the materials synthesized from cadmium acetate still have the optimal hydrogen evolution performance.The hydrogen evolution performance of the photocatalyst synthesized by cadmium nitrate and thioacetamide is greatly improved compared to the composite material synthesized by cadmium nitrate and thiourea,which due to the successful loading of MoS2. |
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