Synthesis and Characterization of N-doped Hollow TiO2 Microspheres

Polystyrene (PS) microspheres were synthesized by emulsion-free polymerization Based on the PS microspheres template, PS/TiO2 (core/shell) microspheres were prepared through sol-gel nanocoating using ammonia/triethanolamine as a catalyst system The N-doped anatase hollow TiO2 microspheres were obtained after calcinations of the PS/TiO2 microspheres Triethanolamine played an important role in the preparation of the hollow TiO2 microspheres It was an inhibitor of the sol-gel process, as well as an N source of the N-doped hollow TiO2 microspheres The effects of the amounts of ammonia, triethanolamine and tetrabutyl titanate on the morphology and size of TiO2 shells were investigated, respectively The surface of the PS/TiO2 microspheres became smooth with increasing the amounts of triethanolamine or decreasing the amounts of ammonia Thicker TiO2 shells were achieved when increasing the amounts of tetrabutyl titanate The content of N doping in the hollow TiO2 microspheres could be easily adjusted by varying the amounts of triethanolamine In addition, the N-doped hollow TiO2 microspheres possessed the optical response to the visible light and presented photocatalysis under visible light