In-situ synthesis of CoP co-catalyst decorated Zn0.5Cd0.5S photocatalysts with enhanced photocatalytic hydrogen production activity under visible light irradiation

Abstract

The generation of hydrogen (H2) through photocatalytic water splitting with the employment of various co-catalysts has attracted much attention. In this study, the CoP was successfully decorated on Zn0.5Cd0.5S as a highly efficient co-catalyst via a two-step in-situ chemical deposition method. The chemical as well as photophysical properties of the as-obtained CoP/Zn0.5Cd0.5S samples were characterized by X-ray diffractometry (XRD), Transmission electron microscope (TEM), UV–vis diffusion reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and surface photovoltage spectroscopy (SPV). The CoP/Zn0.5Cd0.5S composite sample with 5% molar content showed the highest photocatalytic H2 evolution activity with a corresponding H2 evolution rate of 734umolh−1, which was about 20 times higher than that of pure Zn0.5Cd0.5S sample and 2 times higher than Pt loaded Zn0.5Cd0.5S sample under visible light irradiation. The photocatalytic activity of the CoP/Zn0.5Cd0.5S composite sample was stable even after 4 cycling photocatalytic experiments. A possible mechanism on the photocatalytic enhancement of CoP was systematically investigated, which can provide a novel concept for the synthesis of other desirable photocatalytic materials with high photocatalytic performance.