A facile one-pot synthesis of highly luminescent CdS nanoparticles using thioglycerol as capping agent

摘要

Highly luminescent, multicolored CdS nanoparticles (NPs) with size less than 3 nm were prepared by aqueous precipitation method using thioglycerol (TG) as the capping agent. The size of the NPs could be successfully controlled by varying TG concentration in the reaction mixture. The as-synthesized NPs were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy, micro Raman, UV–Vis and photoluminescence (PL) spectroscopy. The XRD results revealed the transformation of zinc-blende cubic CdS to hexagonal wurtzite phase at higher capping agent concentration, which coincides well with TEM results. Raman spectra demonstrated a notable decrease in the peak intensity and the disappearance of 2 LO phonon mode of CdS upon TG addition. UV–Vis absorption spectra showed a remarkable blue shift in absorption edge in TG-capped CdS NPs compared to the uncapped one. With an increase in the capping agent concentration from 0 to 0.2 molar, the broad PL band at 630 nm blue shifted to 600 nm accompanying a gradual increase in the intensity of PL emission.