Au nanoparticle-decorated ultrathin CdS nanowires for high-efficiency photodegradation of organic dyes

Abstract

CdS nanowires (NWs) are obtained by the sulfurization of Cd(OH)2 nanowires at room temperature using H2S. The CdS NWs with diameter of 2–5 nm exhibit high photocatalytic performance due to the ultrafine size. To further improve the performance, Au nanoparticles (NPs) with different sizes, i.e., 5, 20, 40 and 100 nm, that decorated the CdS NWs are synthesized through a simple self-assembly and solid sulfuration process. The synthesized Au NPs–CdS NWs hybrids show higher photocatalytic efficiency than that of pure CdS NWs. Furthermore, 20 nm Au NPs–CdS NWs hybrids with an optimal Au loading of 3.2 wt% exhibit the highest photocatalytic efficiency. Both the enhanced separation of photoinduced hole–electron pairs and the absorption of visible light by incorporating Au NPs significantly improve the photocatalytic performance.