Photocatalytic Performance of SnO2 Coupled CdO Nanoparticles Against MY and RhB Dyes

Precipitation method is adopted to synthesize CdO, SnO 2 and CdO-SnO 2 nanocomposite. Characterization of the synthesized CdO, SnO 2 and CdO-SnO 2 composite was done by x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy and photoluminescence (PL) spectroscopy. In the XRD pattern of the composite, cubic CdO and tetragonal SnO 2 peaks were observed. The existence of Cd, Sn and O in CdO-SnO 2 was confirmed from the XPS spectrum. FTIR spectrum of the composite ascertained the presence of peaks associated with Cd-O and Sn-O bonds. The band gap of pure CdO got blue shifted from 2.49 eV to 2.94 eV when coupled with SnO 2 . Photodegradation efficiencies of 89.41% and 82.25% were observed by the composite under visible light against metanil yellow (MY) and rhodamine B (RhB) dyes, respectively, which were quite high compared with that of pure CdO and SnO 2 . Increased life time of carriers due to their effective separation might have enhanced the degradation ability of the composite. The CdO-SnO 2 composite catalyst seems to be more stable.