Preparation of hollow TiO2 microspheres by the reverse microemulsions

Abstract TiO 2 hollow microspheres were prepared by the reversed microemulsions, in which TiCl 4 solution were reacted with ammonia in water/(TX-100 + n-pentanol)/cycloheptane. The structures of TiO 2 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 TiO 2 hollow microspheres is affected by the concentrations of TiCl 4 . Sizes of particles do not increase as [water]/[TX-100] mole ratios ( W ) increases from 10 to 20; The anatase titania was confirmed by XRD analysis when calcined at 600 °C. The possible formation mechanism of hollow TiO 2 spherical structures has simply been proposed.