Enhanced photocatalytic activity of Co doped SnO2 nanoparticles by controlling the oxygen vacancy states

Abstract Co doped SnO2 nanoparticles were synthesized by chemical precipitation. Excess Co ions as doping element were used to compensate the deficit of oxygen from SnO2 lattice. The crystalline structure of all samples corresponds to tetragonal rutile crystalline phases of tin oxide and the crystallinity increases by doping. The nanoparticles shape is polyhedral with narrow distribution. The presence of Co ions in SnO2 lattice results in decreasing the oxygen deficiency. All the doped samples show the red shift in optical response. Photoluminescence emission spectra show peaks in UV and visible region. Visible emissions decrease by doping which indicate lower recombination rate of photogenerated electron-hole pairs. All the samples show photocatalytic activity against RhB synthetic solution under visible light irradiation, the best performance was obtained using 1.0%Co–SnO2. The mechanism of photocatalytic activity was explained based on the reactive oxygen species generated by nanoparticles under visible irradiation in correlation with structural and optical information obtained in this study.