Boosting the photocatalytic hydrogen production activity of marigold-like Zn2In2S5 by using noble-metal-free Ni2P as cocatalyst

Abstract

To enhance the activity of photocatalysts, it is crucial to use non-noble metal as a cocatalyst instead of noble metal in the arena of photocatalysis. In this study, to boost the photocatalytic hydrogen activity of pristine Zn2In2S5, XNi2P/ZIS5 composite photocatalysts were prepared using noble-metal-free Ni2P as cocatalyst. Before photocatalytic hydrogen production experiments, the physicochemical properties of the synthesized materials were systematically characterized by advanced characterization methods. The experiment results demonstrate that the load of Ni2P cocatalyst can noticeably enhances the photocatalytic performance of Zn2In2S5 and the photocatalytic hydrogen generation activities are observably influenced by the mass ratio of Ni2P to Zn2In2S5. Among XNi2P/ZIS5, the 10Ni2P/ZIS5 sample presents the optimal hydrogen production rate of 17.74 mmol g−1 h−1, which is 7.58 times as high as that of pristine Zn2In2S5. The increased photocatalytic hydrogen evolution activity could be attributed to the introduction of noble-metal-free cocatalyst Ni2P, which serves as an electronic collector and reduction sites remarkably facilitates the separation and migration of photoexcited electrons of Zn2In2S5. Meanwhile, the rate of reactions is significantly accelerated.