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

TiO 2 /SiO 2 /Ag/Ag 2 O and TiO 2 /Ag/Ag 2 O nanocomposite spheres have been synthesized via a low-temperature hydrothermal method using SiO 2 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 Ag 2 O nanoparticles were successfully deposited on the surfaces of TiO 2 /SiO 2 nanocomposite spheres and porous TiO 2 nanospheres forming nanoheterojunctions. The photocatalytic experiment results reveal that all the as-prepared catalysts possess improved photocatalytic activities compared with P25 nanoparticles. Both TiO 2 /SiO 2 /Ag/Ag 2 O and TiO 2 /Ag/Ag 2 O 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.