Effects of oxygen vacancy and sintering temperature on the photoluminescence properties and photocatalytic activity of CeO2 nanoparticles with high uniformity

Gamma-ray irradiation assisted polyacrylamide gel route was applied to synthesize the homogeneous CeO2 nanoparticles. XRD results and optical properties indicates that the vacancy concentration and the energy gap (Eg) value of CeO2 nanoparticles increases with the increasing crystallite size. Photoluminescence experiment indicates that a small number of -CH and -CH2, and C-O functional groups in presence of the CeO2 nanoparticles can help improve the photoluminescence properties of CeO2 nanoparticles. Photocatalytic experiment results indicate that the pure CeO2 nanoparticles exhibits an obviously enhanced photocatalytic activity due to its have higher vacancy concentration. The dye concentration of 5 mg L-1 and the catalyst concentration of 1 g L-1 were fixed for photocatalytic degradation of methylene blue (MB) dye. In addition, the CeO2 nanoparticles containing -CH and -CH2, and C-O functional groups exhibits an outstanding adsorption capacity, however, it is not advantageous to the photo-degradation of MB dye. Based on the experimental results, a possible photocatalytic mechanism for organic decorated the CeO2 nanoparticles are discussed.