Preparation of hollow TiO2 microspheres by the reverse microemulsions

TiO2 hollow microspheres were prepared by the reversed microemulsions, in which TiCl4 solution were reacted with ammonia in water/(TX-100+n-pentanol)/cycloheptane. The structures of TiO2 hollow microspheres prepared in different conditions were characterized by SEM and XRD. The results show that the particles have hollow structures and their shell thickness is very thin. The shell thickness of TiO2 hollow microspheres is affected by the concentrations of TiCl4. Sizes of particles do not increase as [water]/[TX-100] mole ratios (4) increases from 10 to 20; The anatase titania was confirmed by XRD analysis when calcined at 600 degrees C. The possible formation mechanism of hollow TiO2 spherical structures has simply been proposed. (c) 2007 Elsevier B.V. All rights reserved.