Investigation on graphene and Pt co-modified CdS nanowires with enhanced photocatalytic hydrogen evolution activity under visible light irradiation

Abstract

Hydrogen evolution by photocatalytic water splitting has attracted extensive attention in recent years. Here we report a composite photocatalyst, in which graphene and Pt particles act as cocatalysts to modify CdS nanowires. This composite photocatalyst was prepared by a solvothermal method followed by a photoreduction process. The obtained samples were characterized by X-ray powder diffraction, UV-vis diffuse reflectance spectroscopy, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence and Brunauer–Emmett–Teller specific surface area analysis. The graphene and Pt comodified CdS nanowires gain a high hydrogen evolution rate of 3984 μmol h⁻¹ g⁻¹, which is almost 4 times higher than that of bare CdS nanowires and also higher than the sum of graphene–CdS and Pt–CdS nanowires. The obtained sample also exhibits a good stability. The encouraging results presented here can be attributed to the incorporation of graphene and Pt which show a synergetic effect for hydrogen evolution. This work paves a way to the potential application of CdS nanowires in energy conversion.