A Z-scheme heterostructure constructed from ZnS nanospheres and Ni(OH)2 nanosheets to enhance the photocatalytic hydrogen evolution

Abstract

The exploration of Z-scheme heterojunction photocatalysts is considered crucial to improve the efficiency of photocatalytic hydrogen evolution. In this work, ZSN with a Z-scheme heterojunction is prepared by a two-step hydrothermal method. Through the study of the surface morphology, crystallization properties, surface chemistry and optical properties of the photocatalyst, it is known that the ZSN heterojunction can improve the visible light capture ability, prolong the service life of charges, improve the efficiency of charge separation, and improve the photocatalytic performance. Under visible light irradiation, the amount of hydrogen evolution of the optimized 2-ZSN is 74 μmol, 37 times that of the pure ZnS (2 μmol). The results of photoluminescence (PL), ultraviolet-visible (UV-Visible) and electrochemical techniques show that the Z-scheme mechanism is advantageous to the separation of photogenic carriers as well as the hole transfer and separation. This work provides a reliable strategy for constructing efficient Z-scheme heterojunction photocatalysts.