Synthesis and enhanced gas sensing properties of Au-nanoparticle decorated CdS nanowires

CdS nanowires (NWs) with an average diameter of 30 nm were synthesized by a solvothermal method and then Au nanoparticles with a size of 10–25 nm were decorated on the surface of the as-synthesized CdS NWs through a simple deposition process. The ethanol sensing properties of CdS NWs and Au-nanoparticle decorated CdS NWs with different Au content were investigated. The results showed that Au nanoparticle-decorated CdS NWs could enhance the response of CdS NWs to ethanol. Especially, the Au–CdS NWs with a proper Au decorating content showed the highest response to 100 ppm ethanol (about 110) which was 5 times higher than that of the CdS NWs as well as fast response/recovery speed (less than 15 s and 5 s, respectively) and excellent selectivity. In addition, the mechanism of CdS NWs and Au nanoparticle-decorated CdS NWs were discussed.