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

Abstract

Precipitation method is adopted to synthesize CdO, SnO2 and CdO-SnO2 nanocomposite. Characterization of the synthesized CdO, SnO2 and CdO-SnO2 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 SnO2 peaks were observed. The existence of Cd, Sn and O in CdO-SnO2 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 SnO2. 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 SnO2. Increased life time of carriers due to their effective separation might have enhanced the degradation ability of the composite. The CdO-SnO2 composite catalyst seems to be more stable.