Ag/AgCl modified self-doped TiO2 hollow sphere with enhanced visible light photocatalytic activity

The Ag/AgCl modified self-doped TiO2 hollow spheres were successfully prepared firstly by a sol-gel method using carbon sphere as template and subsequently deposition-precipitation and photo-reduction process. Characteristics and properties of the products were investigated using X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the self-doped TiO2 hollow spheres, with diameters about 800-950 nm and shell thickness of 20-30 nm, are constituted with thousands of self-doped TiO2 nanoparticles with diameters of 20-30 nm. Ag/AgCl modified self-doped TiO2 hollow spheres showed broad absorption in the region of 400-700 nm arising from surface plasmon resonance of Ag nanoparticles. The as prepared samples showed improved solar light and visible light induced photocatalytic activities by decomposing Rhodamine B. The improved visible light photocatalytic activities may be due to the oxygen vacancies and Ti3+ localized states of the self-doped TiO2 hollow spheres and the surface plasmonic resonance effect.