Preparation of SnO2 Nanoparticles with Addition of Co Ions for Photocatalytic Activity of Brilliant Green Dye Degradation

Pure and cobalt (Co)-doped tin oxide (SnO2) nanoparticles were prepared by using a simple co-precipitation method, and the effect of doping on structural, morphological and optical properties was studied. X-ray diffraction revealed a cassiterite tetragonal SnO2 structure with the space group of P4(2)/mnm and without crystalline phases for the samples-doped with higher concentrations. The average crystalline size was found to be between 26.4nm and 23.1nm. Fourier-transform infrared spectra depicted the presence of O-H, C-H and Sn-OH absorption bands. It was observed from ultraviolet-visible spectra that the optical band gap values were decreased from 3.69eV for pure SnO2 to 3.47eV for 7% Co-doped SnO2. The photolumenescene emission spectra showed that the defect- and emissions-related peaks and the intensity of the peaks decreased with increasing Co concentrations. The presence of tin, oxygen and Co species were found from energy dispersive x-ray spectra. The photocatalytic activities of pure and Co-doped SnO2 nanoparticles were investigated by studying the photodecomposition of brilliant green dye, an organic pollutant. The 7% Co-doped SnO2 had higher photocatalytic activity compared to the pure SnO2, and a maximum degradation efficiency of 91% has been obtained under visible light irradiation.