Synergistic effect of bimetallic cobalt-based sulfide enhances the performance of ZnSe photocatalytic hydrogen evolution by Z-scheme

Abstract

In this work, ZnSe/ZnCo2S4 (ZCS) composites were synthesized by simple hydrothermal method and Z-scheme heterojunctions were formed. Under the simulated sunlight environment, The results show that the hydrogen production efficiency of 70 wt% ZnSe/ZCS composites was as high as 3402.4 μmol·g−1·h−1, which is 4.37 and 94.44 times that of ZnSe and ZCS monomers, respectively, and the apparent quantum efficiency (AQY) reaches 10.5%. Among them, the Z-scheme heterojunction improves the redox ability of the material, which is more conducive to charge separation, and ZCS also promotes absorption of visible light of ZnSe/ZCS. In addition, the Z-scheme heterojunction structure and material stability were verified by XPS, ESR.This work provides a new way to improve ZnSe in the field of photocatalytic hydrogen evolution.