ZnIn₂S₄-based Heterostructure Modulation And Its Photocatalytic Hydrogen Production Performance

Indium zinc sulfide（ZnIn₂S₄）stands out among many photocatalysts with visible light responsiveness,mainly due to its advantages of proper band gap,adjustable morphology,chemical stability.However,ZnIn₂S₄,which has been extensively studied so far,is not without drawbacks,such as:the separation process after the carrier is excited is not ideal;the unavoidable photocorrosion of the sulfide itself.Combined with the current situation,we comprehensively analyzed the heterojunction mechanism used by various types of co-catalysts for construction and the clever design of various micro-heterointerfaces,and carried out the following heterogeneous structure controllable modulation of Zn In₂S₄ and its research on the performance of hydrogen production by photocatalysis.Firstly,from the perspective of ZnIn₂S₄ bulk phase adjustment（building a core-shell heterostructure）,using in-situ hydrothermal operation on a pre-prepared layered spherical ZnIn₂S₄ core,with CuIn S₂ as the shell growth.At the same time,the typical p-type semiconductor Cu InS₂ material and the traditional n-type Zn In₂S₄ interface form a p-n junction.A series of structural characterization confirmed the accurate formation of the core-shell structure of CuInS₂@ZnIn₂S₄ material.Enhanced photocatalytic hydrogen production activity confirms the excellent performance of CuInS₂@ZnIn₂S₄ composite.The optimal hydrogen evolution rate of 292μmol·h^-1·g^-1 is 4 times that of pure Zn In₂S₄.The mechanism of Cu InS₂@Zn In₂S₄ performance enhancement was explored by photoelectrochemical performance characterization.It is confirmed that the CuInS₂@ZnIn₂S₄ core-shell structure has excellent carrier separation efficiency and broadened light absorption range.In addition,considering the surface modulation scheme of Zn In₂S₄,the onion ring-shaped MoS₂ thin-layer nanomaterials synthesized by solvothermal reaction were used as seeds to induce the growth of ZnIn₂S₄ in the hydrothermal reaction after being homogeneous with the precursor of Zn In₂S₄.A series of structural characterization confirmed that a heterogeneous material with a special structure of MoS₂/ZnIn₂S₄,which was tightly coupled in a 2D-2D manner,was accurately formed.In terms of photocatalytic performance,the rate of catalytic hydrogen evolution(423μmol·h^-1·g^-1)of the new MoS₂/ZnIn₂S₄ composite material in visible light（λ≥420 nm）is 4.6 times that of pure ZnIn₂S₄,and the mechanism of enhancing photocatalytic performance of composite materials was investigated in detail.