A 2D self-assembled MoS₂/ZnIn₂S₄ heterostructure for efficient photocatalytic hydrogen evolution

Abstract

Semiconductor photocatalysis for hydrogen production is a promising route to address current energy demands. It is still a great challenge to spatially separate photogenerated electrons and holes in bulk photocatalysts because of the long carrier transport pathway from the bulk to the surface. 2D heterostructured photocatalysts with the type II band alignment can not only shorten the carrier transport pathway, but also create an electric field at the interface to suppress the carrier recombination. However, ultrathin and intimate-contact 2D heterostructured photocatalysts have rarely been achieved so far. Herein, we reported that ZnIn₂S₄ nanosheets were self-assembled on few-layer MoS₂ nanosheets to fabricate ultrathin and intimate-contact 2D heterostructured photocatalysts. This 2D heterostructure was formed thanks to the strong electrostatic adsorption between MoS₂ and ZnIn₂S₄. Under visible light irradiation, the H₂ evolution rate of 2D MoS₂/ZnIn₂S₄ heterostructured photocatalysts can reach 8898 μmol g^-1 h^-1, which is almost 16 times higher than that of the pure ZnIn₂S₄ photocatalysts. The dramatically enhanced photocatalytic performance was ascribed to the better charge separation and the accelerated surface reaction due to the heterostructure and more active sites provided by MoS₂. These results provided a new insight for the design and development of 2D heterostructured photocatalysts.