Novel triethanolamine assisted sol-gel synthesis of N-doped TiO2 hollow spheres

A facile preparation of N-doped anatase TiO2 hollow spheres in sub-micron size with good morphology was developed in this work. Polystyrene latexes in size of 470 nm were used as the templates to fabricate polystyrene/TiO2 core-shell spheres in the sol-gel process. Here the ammonia/triethanolamine positive/negative catalyst pair was first employed to control the coating of TiO2 onto the surface of the PS templates. And synchronously triethanolamine served also as the N source. The N-doped TiO2 hollow spheres with good morphology were first obtained here after calcinations of the core-shell spheres. It was proved that the hollow spheres have distinct visible light response from 390 to 600 nm. The content of the N doping could be easily adjusted by changing the amount of triethanolamine added and the optical response of TiO2 hollow spheres shifted more to the visible light as the content of the N doping increasing. The N doping could increase the separation efficiency of the photoinduced electron and hole, so the intensity of photoluminescence decreased obviously with increased content of the N doping. (C) 2010 Elsevier B.V. All rights reserved.