Preparation And Photocatalytic Hydrogen Production Performance Of Metal Sulfide-based Heterostructure Catalysts

Metal sulfide has a strong photoresponse under visible light due to its narrow band gap,so it becomes an excellent visible light catalytic material.However,the severe recombination of photogenerated electrons and holes greatly limits the improvement of the photocatalytic efficiency of metal sulfides.In this paper,three types of unit metal sulfide/binary metal sulfide(CdS/ZnIn2S4),unit metal sulfide/unit metal oxide(In2S3/In2O3)and black phosphorus/binary metal sulfide(BP/ZnIn2S4)are constructed respectively.The heterojunction composite catalyst effectively promotes the separation of photo-generated carriers and enhances the photocatalytic hydrogen production activity.Three different methods are used to improve the photocatalytic performance of metal sulfides,including:We have developed a simple two-step solvothermal method to create a new type of atomic heterojunction.First,synthesize CdS nanorods,and then grow twodimensional ZnIn2S4 nanosheets on the surface of the one-dimensional CdS nanorods.The synthesized CdS/ZnIn2S4 heterojunction exhibits better photocatalytic hydrogen production activity than the original CdS,up to 1.29 mmol/g/h.The experimental and theoretical calculation results show that the strong electronic coupling at the interface between CdS and ZnIn2S4 significantly improves the separation efficiency of charge separation,which is the reason why the CdS/Znln2S4 heterojunction exhibits higher catalytic activity.The layered porous hydrangea-like In2S3/In2O3 heterostructure was successfully synthesized through a simple in-situ oxidation process.The formed In2S3/In2O3 heterostructure shows better photocatalytic activity than the individual In2S3 and In2O3.The formed heterojunction greatly promotes the transfer of interface charges.In addition,the formation of a layered porous heterostructure increases the number of active sites and improves permeability,thereby significantly promoting the photocatalytic H2 evolution activity,which can reach a maximum of 136.76 μmol/g/h.We designed a simple two-step solvothermal method to construct a 2D/2D ZnIn2S4 nanosheet/black phosphorus nanosheet(ZIS/BP)heterostructure,which is used to split water under visible light to produce hydrogen and has good cyclicality.The best 2D/2D ZIS/BP heterostructure has enhanced charge carrier separation and abundant active sites.Compared with the ZnIn2S4 nanosheet/black phosphorous nanoflower structure,ZnIn2S4 the nanosheet/black phosphorous nanosheet catalyst has better hydrogen production performance.By adjusting the loading of black phosphorus,the photocatalytic hydrogen production rate of ZIS/BP can be up to 2.0 mmol/g/h.