Preparation of Cerium Doped Titania Hollow Spheres

Hollow spheres attracted extensive attention due to their low density, mechanical and thermal stability, large specific area, surface permeability [1] and their broad range applications such as controlled release capsules of various substances, fillers and catalysts. A variety of hollowspheres have been successfully fabricated by various methods such as template-assisted process including polystyrene latex particles or silica particles and their crystalline arrays, emulsion polymer micelles and ultrasonication [2]. Titania has been extensively investigated during recent years for its superior properties, such as catalytic activity, photoelectrochemical conversion, photocatalysis [3], etc. However, TiO2 displays its highphotoactivity only when it is irradiated by ultraviolet light due to its wide band gap (3.2 ev for anatase phase). An effective way to improve the photocatalytic efficiency is to introduce other metal ions into nano-TiO2 [4]. Ce has an f electron and could introduce new energy level into band gap of nano TiO2. Ce doping leads to electron jumping from valence band to conduct band of TiO2 in visible range with a wavelength over 400 nm [5]. In this work, titania hollow nano spheres doped with cerium were prepared by the sol-gel method and characterized with X-ray diffraction (XRD) and scanning electron microscope (SEM