Materials Research Bulletin, Vol.105, 55-62, 2018
Sol-gel synthesize and characterization of chi Gd2Ti2O7/SiO2 photocatalyst for ofloxacin decomposition
Gd2Ti2O7 was loaded on the surface of quartz spheres by a sol-gel method. The Gd2Ti2O7 maintains the pyrochlore phase after loading. Dispersion of Gd(2)Ti(2)O(7)on the SiO2 spheres reduces crystallite size of Gd2Ti2O7. The surface of SiO2 sphere is coated with a rough layer of Gd2Ti2O7. The band gap energy of the chi Gd2Ti2O7/SiO2 constantly increases with decreasing Gd2Ti2O7 loading content, ranging from 3.35 eV to 3.71 eV. The porous structure in the chi Gd2Ti2O7/SiO2 composite mainly comes from the Gd2Ti2O7 layer. The maximum BET surface area and total pore volume are even larger than that of the unloaded Gd2Ti2O7. The hydroxyl radical generation efficiency during illumination is enhanced after loading Gd2Ti2O7 on SiO2. The 30%Gd2Ti2O7/SiO2 sample has the optimal photocatalytic activity. 65.6% of the initial ofloxacin can be decomposed on 30%Gd2Ti2O7/SiO2 after 30 min of UV light irradiation, as compared to 24.1% on the unloaded Gd2Ti2O.