Synthesis of TiO2/SiO2/Ag/Ag2O and TiO2/Ag/Ag2O nanocomposite spheres with photocatalytic performance

摘要

TiO2/SiO2/Ag/Ag2O and TiO2/Ag/Ag2O nanocomposite spheres have been synthesized via a low-temperature hydrothermal method using SiO2 spheres as templates, combined with a light-induced reduction method and a hydrogen peroxide oxidation process. Scanning electron microscopy, energy-dispersive X-ray and X-ray diffraction analyses have demonstrated that Ag and Ag2O nanoparticles were successfully deposited on the surfaces of TiO2/SiO2 nanocomposite spheres and porous TiO2 nanospheres forming nanoheterojunctions. The photocatalytic experiment results reveal that all the as-prepared catalysts possess improved photocatalytic activities compared with P25 nanoparticles. Both TiO2/SiO2/Ag/Ag2O and TiO2/Ag/Ag2O nanocomposite spheres exhibit excellent photocatalytic performances, which can be attributed to the synergistic effects of different kinds of nanoparticles. The synergistic mechanism of these nanoparticles is also discussed in detail.