The Preparation,Modification And Photocatalytic Performances Of Superior Visible-light Photocatalysts

With the rapid development of the global economy,the environmental and energy crisis have become a sharp problem,especially the water pollution and energy shortage.For resolve the sewage treatment,various technologies have been explored and developed,among them,photocatalysis technology has been favored by the majority of researchers because of its own advantages such as clean and green,thorough degradation and low cost.Hydrogen,as a clean energy with high calorific value,which has attracted worldwide attention.Photocatalytic degradation of organic pollutants in water by solar energy via semiconductor catalysts and photocatalytic decomposition of water to produce hydrogen are one of the effective ways to solve the problems of water environmental pollution and fossil energy shortage.In this work,catalysts BiOI,ZnIn₂S₄ and g-C₃N₄ were mainly prepared and their properties were studied.The research content of this work is as follows:?1?The nanosheet self-assembled microsphere visible light catalyst BiOI was prepared by microwave solvothermal method,and then slightly doped with lanthanide Er to explore the best doping amount of Er.After that,the rGO/Er³⁺-BiOI composite catalyst was finally formed by combining the reduced graphene with the best Er doped BiOI catalyst,and the reason and catalytic mechanism for the greatly improved performance of the composite catalyst rGO/Er³⁺-BiOI have analyzed and evaluated.?2?ZnIn₂S₄ catalyst was synthesized by microwave solvothermal method,MoS₂ was deposited on the surface of ZnIn2S4 catalyst by photodeposition method,and the optimal amount of MoS₂ was explored.Then Au was deposited on the surface of composite catalyst MoS₂/ZnIn₂S₄ by photochemical deposition method to finally form Au/MoS₂/ZnIn₂S₄ composite catalyst and evaluate its photocatalytic performance for hydrogen production by decomposing water.The possible catalytic mechanism was analyzed and discussed.?3?The graphite-like phase g-C₃N₄ was prepared by thermal polycondensation and stripped off and the noble metals Pt,Au,Ag and semiconductor MoS₂ were deposited on the surface of g-C₃N₄ by photodeposition method.The hydrogen production performance of the prepared catalyst have studied and compared,and the possible reasons and mechanisms for its greatly improved hydrogen production performance were discussed.