Self-assembly of 3D Zn0·5Cd0·5S/CoP microflower for efficient visible-light-driven photocatalytic H2 evolution

Abstract

In this work, we design and fabricate a novel Zn0·5Cd0·5S/CoP composite with a 3D microflower structure by a facile hydrothermal method. Comprehensive photochemical measurements showed that the engineering of highly conductive CoP co-catalyst into Zn0·5Cd0·5S solid solution improves the visible light response capability by narrowing the forbidden band gap. At the same time, a morphology control by forming a 3D microflower structure could realize an intimate contact interface between Zn0·5Cd0·5S and CoP, which ensures that electrons from Zn0·5Cd0·5S excited by visible light (420 nm) can be effectively transferred to the highly conductive CoP for separation and migration. The systematic photocatalytic hydrogen evolution experiments illustrate a remarkable hydrogen production rate up to 72.71 mmol h−1 g−1 for Zn0·5Cd0·5S/CoP with a CoP mass fraction of 20 wt%, which is 27 times higher than that of bare Zn0·5Cd0.5S. Based on the characterization analysis results, a possible mechanism of hydrogen production by Zn0·5Cd0·5S/CoP composite catalyst is proposed.