Preparation And Properties Of Metal Polysulfides Catalyst And Its Composite Photocatalyst

In recent years,metal sulfide semiconductor has become a new type of multifunctional inorganic material with excellent physical and chemical properties,and has shown a very broad application prospect,especially in the environmental remediation and clean energy application closely related to people’s lives.However,the narrow band gap of metallic polysulfide is easy to cause the recombination of electrons and holes and photo corrosion,which limits its wide application in practice.In this paper,based on the advantages and disadvantages of metal polysulfide,the following structures are designed and synthesized.The phase structure,morphological characteristics,optical and electrical properties of the three compounds are analyzed by XRD,SEM,TEM,XPS,DRS diffuse reflectance spectroscopy,electrochemical workstation and other characterization methods.The photocatalytic properties of the composite are investigated by hydrogen evolution experiments.1:Using ZnCl₂,Sn Cl₂·2H₂O,Cu Cl₂·2H₂O and thiourea as raw materials,the flower spherical Cu₂Zn Sn S₄（CZTS）was prepared by solvothermal method.And take this as the base material.The CZTS/Cu₂O composite catalyst supported on Cu₂O surface was successfully prepared by constant temperature stirring method.The formation process and mechanism of pure CZTS and flower spherical CZTs/Cu₂O composite synthesized were studied.The composites were studied by XRD,SEM,DRS,XPS and electrochemical workstation.The results showed that the light response current intensity of CZTs/Cu₂O composite under visible light was higher than that of pure CZTS and Cu₂O.Because of the formation of CZTs/Cu₂O heterojunction and the synergistic effect between CZTs and Cu₂O,CZTs/Cu₂O had a high ability to decompose water.The results of hydrogen production experiments showed that the optimal hydrogen production rate of CZTS/Cu₂O was 859.6mol·h^-1,which was 7.7 times higher than that of pure CZTS.In addition,the photocatalytic experiments for four cycles also proved that the CZTs/Cu₂O heterojunction photocatalyst has good stability.2:α-MnO₂ nanorods were prepared by using potassium permanent manganese and acetic acid.Then,hexagonal Zn In₂S₄（ZIS）flower-like nanorods were synthesized by usingα-MnO₂ as template material.Finally,Ag nanoparticles were deposited on the surface of MnO₂/Zn S flower-like nanorods by photochemical deposition method,and the ternary composite materials of Ag/α-MnO₂/ZIS were successfully synthesized.The structure and morphology of Ag/α-MnO₂/ZIS ternary composites were investigated by XRD,SEM,TEM,XPS and DRS.The results showed that the Ag/α-MnO₂/ZIS ternary composite was superior to the pure ZIS andα-MnO₂/ZIS binary composite in terms of light absorption,electrical properties and catalytic reduction ability.The hydrogen evolution rate of Ag/α-MnO₂/ZIS reached 3644 mol·h^-1·g^-1,which was 14.9 times and 1.8 times higher than that of original ZIS andα-MnO₂/ZIS samples,respectively.3:Using carbon nanotubes（CNTs）as bonding materials and ZnCl₃,In Cl₃ and thioacetamide（TAA）as raw materials,CNTs/ZIS composites were successfully prepared by solvent method.The phase,morphology and properties of CNTs/ZIS composites were investigated by XRD,SEM,TEM,DRS,XPS and hydrogen production experiments.The results showed that CNTs/ZIS composites had a strong absorptive capacity in the visible light range.The maximum hydrogen production rate of the material was 8904.5μmol·h^-1·g^-1,which was 13.2 times higher than that of pure ZIS sample(670.2μmol·h^-1·g^-1).The electrical and photocatalytic properties of hydrogen production were superior to those of pure ZIS photocatalyst.figure[31]table[6]references[139]...