AuPd bimetallic nanoparticles decorated Cd_0.5Zn_0.5S photocatalysts with enhanced visible-light photocatalytic H₂ production activity

In this study, novel AuPd bimetallic co-catalyst decorated Cd_0.5Zn_0.5S photocatalyst was successfully synthesized via an in-situ chemical deposition method. The physical as well as the photophysical properties of the as-obtained AuPd/Cd_0.5Zn_0.5S samples were characterized by X-ray diffractometry (XRD), Transmission electron microscope (TEM), UV–vis diffuse reflection spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and surface photovoltage spectroscopy (SPV). The AuPd bimetallic co-catalysts showed dramatic photo-generated charge separation efficiency in Cd_0.5Zn_0.5S sample, and thus significantly enhance the H₂ production activity under visible light irradiation. The AuPd/Cd_0.5Zn_0.5S sample with 0.5 wt% content had the highest catalytic activity, and the corresponding H₂ evolution rate is 3.65 mmol g⁻¹ h⁻¹, which was about 12 times as that of pure Cd_0.5Zn_0.5S sample under visible light irradiation. The photocatalytic activity of the photocatalyst was stable even after 9 cycling photocatalytic experiments. A possible mechanism on the photocatalytic enhancement of AuPd NPs was systematically investigated, which can provide a novel concept for the synthesis of other desirable photocatalytic materials.