Fabrication of 3D CuS@ZnIn2S4 hierarchical nanocages with 2D/2D nanosheet subunits p-n heterojunctions for improved photocatalytic hydrogen evolution

Photocatalysis based on metal sulfide semiconductor is considered as an economic, safe, renewable, and clean technology. However, the availability of photocatalysts is limited by the low solar energy utilization efficiency and the fast recombination of photogenerated electron-hole pairs. Developing a hollow heterostructure photocatalyst based on semiconductors for enhancing solar energy utilization and separation efficiency of photogenerated carriers is crucial in the photocatalytic H 2 production reaction. The as-prepared 3D hierarchical nanocages photocatalyst CuS@ZnIn 2 S 4 with abundant and compact nanosheets 2D/2D hetero-interfaces displayed an improved photocatalytic hydrogen evolution rate as high as 7910 μmol h −1 g −1 in the absence of any cocatalyst. This is the first report of the use of CuS nanosheets-assembled hollow cubic cages to construct 3D hierarchical nanocages photocatalysts. The close distance between the two nanosheet subunits induce the strong interaction, which was advantage to the separation and transfer of charge carriers. In addition, the hollow structure can not only enhance light adsorption, but also suppress photogenerated carrier recombination. The experimental characterizations and theory calculations confirmed that the strong interaction between CuS and ZnIn 2 S 4 2D/2D hetero-interfaces can extremely facilitate the separation of photogenerated charge carriers and accelerate the electrons transfer. The present work provides a feasible method to construct heterojunction photocatalyst for hydrogen evolution via water splitting powered.