Pt3Co-loaded CdS and TiO2 for photocatalytic hydrogen evolution from water

Abstract

A new photocatalyst was prepared by loading 1 wt% of a platinum cobalt alloy on CdS via a simple polyol reduction method. XRD measurements confirmed the composition of the alloy as Pt₃Co. Results from transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) measurements showed that Pt₃Co nanoparticles with an average size of 4 nm were uniformly assembled on the surface of CdS. It was found that the activity of Pt₃Co–CdS was approximately two times higher than that of Pt–CdS for photocatalytic H₂ evolution. Photochemical measurements suggested that the high activity could be attributed to a better accumulation of photoexcited electrons and the higher conductivity of Pt₃Co–CdS than that of Pt–CdS. The Pt₃Co alloy cocatalyst was also loaded on TiO₂, another widely used photocatalyst, and it also exhibited higher activity than pure Pt loaded on TiO₂. This demonstrates the potential of Pt₃Co as a universal cocatalyst.