Enhanced Photocatalytic Activity of Coinage Metal-Cadmium Sulfide Nanorod Composites under Sun Light Irradiation

摘要

The effect of Au, Ag & Cu (1 wt%) photodeposition onto CdS nanorod (length ~ 116 nm, aspect ratio = 21, surface area = 81 m~2/gm) has been studied by photocatalytic degradation of 0.5 mM salicylic acid both under direct sunlight and UV (125 W Hg arc lamp, 10.4 mW/cm~2) irradiation. The bare CdS nanorod (NR) exhibited higher photoactivity as compared to low activity of bare CdS (~10 nm) nanosphere (NS) and Au & Ag photodeposition highly improved the CdS nanorod photoactivity compared with Cu deposition. The fluorescence emission of CdS nanorod at 479 nm is also quenched due to metals deposition. It is observed that Au-CdS (20 mg) nanorod composites completely degrade 0.5 mM (20 ml) salicylic acid within 2 h sun light exposure. The significant effect of Au-CdS photocatalytic activity on the various sizes (3.5 & 2 nm) of Au deposits has been observed during salicylic acid photodegradation.