Preparation of TiO2 Nanoparticles Doped with Cs+ and Sr2+ and Their Photocatalytic Activity Under Solar Light

摘要

Using cesium nitrate and strontium nitrate as doping metal ions source,Cs-doped TiO2 and Sr-doped TiO2 photocatalysts were successfully synthesized through the hydrolysis of tetrabutyl titanate by an acid-catalyzed sol-gel method.The photocatalytic activities of these catalysts prepared at 600 °C for 2 h were evaluated by the degradation of methyl orange in aqueous solution under solar light irradiation,and the as-prepared samples with higher photocatalytic efficiency were characterized by means of X-ray diffraction (XRD) and UV-Vis absorption spectroscopy.The XRD patterns indicate that the crystal structure still remains as anatase phase for the doped samples,and the average crystal size of TiO2,0.1 at% Cs-doped TiO2 and 0.3 at% Sr-doped TiO2 is 21.3,13.1 and 10.8 nm,respectively.The band gap absorption shows red shift to the visible region for the doped samples from the UV-Vis spectrogram.The results show that the photocatalytic activity of TiO2 nanoparticles doped with Cs+ and Sr2+ exhibits a significant improvement and their degradation efficiencies are more than 30% in comparison with those of TiO2 under the same condition,and the optimal doping concentration is determined to be 0.1 at% and 0.3 at% for Cs+and Sr2+,respectively.