Fine-tuning the photoluminescence and photocatalytic properties of CdS nanorods of varying dimensions

CdS nanorods having different aspect ratio viz., 17 (length ∼170 nm and width ∼10 nm) and 28 (length ∼140 nm and width ∼5 nm) has been synthesized by solvothermal technique at different time intervals (2–10 h). The effect of aspect ratio, crystallinity, band gap energy, surface area and Au/Ag loading on the various photoactive properties of these CdS nanostructures are discussed here. The photocatalytic activity for salicylic acid oxidation under UV irradiation is gradually improved with the increasing crystallinity of CdS nanostructures, length (140 < 170 nm), exposed area (2358 < 5722 nm2) per particle and decreasing surface area (158 < 122 < 76 m2g−1), surface to volume ratio (0.82 < 0.41 nm−1) and aspect ratio (28 < 17). The deposition of 1–2 wt% Au (∼3.5 nm) and Ag (∼1.8 nm) nanoparticles onto CdS drastically quenched the emission and enhanced the photocatalytic activity.