In/Co-sulphide Modified CdS Nanoarry@MoS₂ For Photoelectrochemical Hydrogen Evolution Reaction

Hydrogen energy is known as the clean energy in the 21st century.Hydrogen energy has high combustion calorific value and pollution-free product.The use of hydrogen energy is a powerful means to alleviate environmental pollution and weaken the energy crisis.One of the preparation methods of hydrogen is the photoelectriccatalytic hydrogen evolution,which have simple operation and high efficiency.The preparation of catalyst is of great importance in hydrogen evolution reaction.The development of effective catalyst for hydrogen evolution reaction is the key to solving energy problems.Many people use cadmium sulfide as a catalyst for photoelectric catalytic hydrogen evolution due to the suitable band structure and excellent light absorption performance.However,photocorrosion and the recombination of photogenerated electron-hole affect its catalytic performance.Therefore,it is necessary to find other metal sulphides as co-catalysts.Due to its special lamellar structure and suitable energy band matching with cadmium sulfide,molybdenum disulfide is considered as our ideal choice.In this paper,In/Co-sulphide modified CdS nanoarray@MoS2 catalysts was investigated.In/Co-sulphide was introduced to facilitate the reaction.According to the different compounds of In/Co-sulphide,two compound systems of CdS nanoarray@MoS2 were designed,whose photo-and electrochemical properties were further studied.The research content of this paper are as follows:CdS@MoS2/In2S3 core-shell nanoarrays were prepared by two-step hydrothermal method using cadmium nitrate as the source of cadmium,sodium molybdate as the source of molybdenum,and indium chloride as the source of indium.The separation efficiency of electrons and holes of the ternary composite catalyst was improved,and its light absorption range and intensity were further expanded compared with CdS or CdS/MoS2(or CdS/In2S3).Under the bias of-0.16 V vs.RHE,the light response current was enhanced to 0.5 mA cm-2.At the same time,through linear sweep voltammetry(LSV),we found that CdS@MoS2/In2S3 showed higher efficiency than the original CdS nanorod or CdS/MoS2(or CdS/In2S3)with or without light illumination.The maximally exposed In-doping MoS2 edges,is supposed to be responsible for the enhanced photoelectrocatalytic activity of CdS@MoS2/In2S3.CdS@CoMo2S4/MoS2 was prepared on ITO by two-step hydrothermal method.The introduction of cobalt can increase both the active sites and the conductivity.The optimum temperature conditions for the preparation of the composite catalyst were obtained by adjusting the reaction temperature.We can tune the ratio of MoS2/CoMo2S4 by controlling the preparation time or the ratio of precursor of Co/Mo,which affect the photo-and electrocatalytic properties of the catalysts.The catalyst with predominant MoS2 phase shows superior photocatalytic hydrogen evolution performance with a high H2 production rate of 46603?mol h-1 g-1.Meanwhile,the catalyst with predominant phase of CoMo2S4 exhibited not only relatively low overpotential of 172 mV at 10 mA cm-2,which outperforms most values that have been reported on catalyst supported on ITO substrate,but also possesses H2 production rate of 23466 ?mol h-1 g-1.