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

•Novel CoP/Cd0.5Zn0.5S photocatalysts were synthesized via an in-situ method.•The CoP/Cd0.5Zn0.5S shows significantly enhanced photocatalytic activity.•The intimate interfaces promote the charge transfer and separation.•The mechanism was proposed and confirmed by SPV result.

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 734 umol h−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.

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