Insight into the function of noble-metal free Cu3P decorated Zn0.5Cd0.5S for enhanced photocatalytic hydrogen evolution under visible light irradiation-- mechanism for continuous increasing activity

The development of low-cost photocatalysts for highly efficient and durable photocatalytic H 2 evolution under visible light is of great challenge. In present study, a Z-scheme Cu 3 P/Zn 0.5 Cd 0.5 S is fabricated via in-situ phosphidation method for efficient visible-light-driven H 2 evolution. The wide light absorption property of Cu 3 P enhances the visible light absorption of Cu 3 P/Zn 0.5 Cd 0.5 S. The electrical conductivity of metallic Cu 3 P and the Z-scheme constructure of Cu 3 P/Zn 0.5 Cd 0.5 S accelerate electron transport rate. The Cu 3 P/Zn 0.5 Cd 0.5 S catalyst achieves highest hydrogen evolution rate of 2.7 mmol g −1 h −1 , which is 3.1 folds higher than that of pristine Zn 0.5 Cd 0.5 S. More interestingly, the Cu 3 P/Zn 0.5 Cd 0.5 S exhibited increasing H 2 production during reaction. The further reduction of PO 3 3− →P &− and the further formation of Cu 3 P is determined to be the key reason for increasing activity. Besides, Cu 3 P/Zn 0.5 Cd 0.5 S prepared by in-situ phosphidation method shows much better catalyst property and performance than that prepared by afterwards mixing method, and the possible reasons for such difference is proposed in present study.