Highly Efficient Deposition Method of Platinum over CdS for H2 Evolution under Visible Light

Pt is one of the most effective cocatalysts used in hydrogen evolution. The efficient and optimum use of Pt is of great importance. In the present work, CdS loaded with Pt was synthesized via a coprecipitation method and annealing treatment, which exhibit remarkably higher efficiency for hydrogen evolution from water splitting compared with the traditional loading methods, i.e., photodeposition or impregnation under visible light. The effects of annealing temperature and different sacrificial reagents on H-2 evolution have been systematically studied. The crystal phase, morphology, and optical and electrical properties of obtained catalysts were well-characterized by X-ray diffraction, transmission electron microscopy, UV-vis spectroscopy, and surface photovoltage tester, respectively. The valence state and loading amount of Pt were investigated by X-ray photoelectron spectroscopy and inductively coupled plasma. The enhanced photocatalytic activity of Pt/CdS by the coprecipitation method is mainly attributed to the intimate contact between Pt and CdS, as well as the efficient deoxidization of Pt4+ to Pt-0 by annealing treatment.