Preparation and photocatalytic properties of mixed-phase titania nanospheres by laser ablation

Laser ablation technique was adopted to prepare titania nanospheres; scanning electron microscope (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM) were employed to characterize the morphology and structure of the product. The results demonstrate that TiO2 nanospheres with mixed-phase (rutile and anatase) structure were successfully fabricated by laser ablation of titanium target in water. We proposed that changed temperature and pressure after the laser ablation is responsible for the co-existence of the rutile phase and the anatase phase. The mixed-phase titania nanospheres (MTNSs) show superior photocatalytic properties compared with commercial titania powder, which is ascribed to the mixed-phase structure. (C) 2009 Published by Elsevier B.V.