Highly efficient visible-light-driven photocatalytic hydrogen production on Cu7S4/Zn0.2Cd0·8S p-n binary heterojunctions

In this work, a series of Zn x Cd 1-x S solid solutions are firstly prepared by a solvothermal process. The optimized composition of Zn x Cd 1-x S solid solution is determined to be Zn 0·2 Cd 0.8 S. On this basis, the Cu 7 S 4 /Zn 0·2 Cd 0·8 S composite photocatalyst with a binary p-n heterojunction has been synthesized by a co-precipitation process followed by a solvothermal method . Owning to the synergistic effect of the heterojunction structure in the interface of Cu 7 S 4 (p-type) and Zn 0·2 Cd 0·8 S (n-type) and the built-in electric field in binary p-n heterojunction, the as-prepared Cu 7 S 4 /Zn 0·2 Cd 0·8 S composite photocatalyst exhibits a significantly improved photocatalytic activity toward hydrogen production from water with visible light response, which is approximately 5.0 times and 16.5 times higher than of pristine Zn 0·2 Cd 0·8 S and CdS, respectively. The possible photocatalytic mechanism has been proposed basing on a series of experimental results. The current work might be valuable inspirations for designing highly efficient heterojunction composite photocatalyst for solar hydrogen evolution .