Design And Study Of Multiphotocatalytic Reaction Systems Based On Ni-Mo-S/ZnIn₂S₄ Composite

Semiconductor water splitting hydrogen evolution technology is an effective way to solve the problems of environmental pollution and energy shortage.The terpolymer metal sulfide indium zinc sulfide（ZnIn₂S₄）has attracted much attention due to its narrow band gap,good stability and strong photoelectric conversion ability.However,the photocatalytic efficiency of single ZnIn₂S₄ is obviously limited due to its high photocarrier recombination rate under light irradiation.In this paper,high efficient and stable Ni-Mo-S/ZnIn₂S₄composite photocatalyst was prepared by using Ni doped Mo S₂（Ni-Mo-S）as cocatalyst and ZnIn₂S₄ composite photocatalyst.The main research contents of this paper include:1.ZnIn₂S₄ and Ni-Mo-S were prepared by simple hydrothermal method.The morphology,structure,elemental composition and valence state,light absorption characteristics and charge separation and transfer of the samples were characterized by SEM,TEM,XPS,UV-Vis DRS and PL,respectively.2.The Ni-Mo-S/EY dye sensitization system and Ni-Mo-S/ZnIn₂S₄ composite photocatalytic system were designed,and the photocatalytic performance was studied through the experiment of photohydrolysis water hydrogen evolution.The experimental results of dye sensitization photodissociation system showed that the optimal hydrogen evolution rate of Ni-Mo-S under EY sensitization was 2.26 mmol h^-1 g^-1,which was 2.72 times that of pure EY system.The experimental results of hydrogen evolution in Ni-Mo-S/ZnIn₂S₄ composite photocatalytic system show that the optimal hydrogen evolution rates in lactic acid solution（acidic medium）and Na₂S/Na₂SO₃ solution（alkaline medium）are 6.07 mmol h^-1 g^-1 and 3.63 mmol h^-1 g^-1,respectively.The hydrogen evolution performance of pure ZnIn₂S₄ is 5.28 times and 2.33 times,respectively.The results show that Ni-Mo-S as catalyst can significantly enhance the photocatalytic hydrogen evolution performance of the corresponding system.3.Construct and optimize the atomic structure model of Ni-Mo-S,and calculate and analyze the binding energy,band structure,state density,differential charge density and optical properties of Ni-Mo-S based on first principles.Theoretically,It is further confirmed that Ni-Mo-S nanosheets have excellent photocatalytic activity.