The synthesis of bayberry-like mesoporous TiO2 microspheres by a kinetics-controlled method and their hydrophilic films

Superhydrophilic film without UV irradiation consisting of bayberry-like mesoporous TiO2 microspheres was prepared by a simple hydrothermal method combined with spinning-coat method. The crystal structure and surface morphology of mesoporous TiO2 microspheres could be adjusted by controlling the reaction kinetics of hydrolysis and condensation of titanium tetrachloride in water/urea aqueous mixtures. The results showed that the surface morphology of TiO2 changed from “papilla”, “roughness” to “smooth” and the crystal structure also changed from rutile to anatase, with the amount of usage of urea from 0 to 2 g. The film consisting of bayberry-like TiO2-1.68 sample had a water contact angle of 2o without UV irradiation, and the superhydrophilic property could be ascribed to the cooperative effect between surface roughness and high densities of surface hydroxyl groups. It demonstrated that the nanoflower mesoporous TiO2 microspheres with a rough surface could be obtained by kinetics controlled method, which could provide a new method for designing mesoporous TiO2 with different structure, surface morphology and multi-functionality.