Preparation Of MoS₂ Composites And The Performance Of Photocatalysis Research

People's demand for energy is increasing day by day,and traditional fossil fuel combustion has brought a series of environmental pollution problems,which contradicts the current theory of sustainable development,and the number of fossil fuels is gradually decreasing.Therefore,the development of clean and renewable energy is the focus of scientific research.As a clean and pollution-free green energy,hydrogen energy can be applied to the conversion between different energy sources and substances to achieve industrial applications.Moreover,hydrogen is ubiquitous in nature.Finding a feasible synthesis method can alleviate the current energy crisis and environmental pollution.MoS₂ is a kind of non-noble metal material with narrow band gap,which has low photocatalytic activity for hydrogen production.While TiO₂ has adjustable morphology and the characteristics non-toxic and non-polluting.In this paper,homogeneous morphology of MoS₂/TiO₂ composite semiconductor photocatalyst was prepared by hydrothermal method,and the photocatalytic performance of the photocatalyst for aquatic hydrogen production was studied.The results show that the catalyst has a uniform wafer shape.Under simulated sunlight irradiation,with the increase of MoS₂ loading,the hydrogen production efficiency increases first and then decreases.The hydrogen production of 6.0%MoS₂/TiO₂ is the highest,reaching to 837.307?mol/?g·h?.This is because the synergistic effect of MoS₂ and TiO₂ promotes the process of hydrogen production.When MoS₂ was loaded on titanium dioxide obtained by calcination of Ti-MOF?MIL-125?,on the one hand,the visible light response range of the catalyst was broadened,and more electrons were produced after irradiation.On the other hand,more active sites of hydrogen production can be generated to promote the reaction.In addition,titanium dioxide had both anatase and rutile structure,heterogeneous phase structure also promoted electron transfer and improved the overall hydrogen production efficiency of the catalyst.In addition,MoS₂/CdS/g-C₃N₄ photocatalyst with novel structure was prepared to further enhance the visible light response of the catalyst,and its photocatalytic performance for water decomposition was studied.The results show that when the mass ratio of CdS to g-C₃N₄ is 5:3under visible light irradiation,the hydrogen production efficiency of CdS/g-C₃N₄heterojunction structure is the highest,reaching to 1097.04?mol/?g·h?.When the optimum ratio of CdS and g-C₃N₄ was determined,we changed the loading capacity of MoS₂.With the increase of MoS₂ loading,the hydrogen production efficiency increased first and then decreases.The photocatalytic activity of 0.5%MoS₂/CdS/g-C₃N₄ was the best,reaching to3446.25?mol/?g·h?,and the catalyst had good stability,which was conducive to recycling.The introduction of MoS₂ promoter accelerates the electron transfer rate,reduces the self-corrosion of CdS and improves the stability of the catalyst.Through this study,it was found that MoS₂ composite catalyst can greatly enhance the photocatalytic hydrogen production effect of the single catalyst,showing excellent photocatalytic activity.