Synthesis and characterisation of fluorinated TiO2 microspheres with novel structure by sonochemical–microwave hydrothermal treatment

AbstractA sonochemical–microwave hydrothermal method for preparing fluorinated mesoporous TiO2 microspheres was developed. Fabrication of mesoporous TiO2 and doping of fluorine were achieved by sonication and then hydrothermal treatment of a solution containing TiO2 precursor sol and sodium fluoride. The average diameter of as synthesised TiO2 microspheres was ∼500 nm. Since the sodium fluoride was doped, rod-like grains (12±0·5 nm) and microporous structure (∼10 nm) formed on the surface, he roughness was clearly increased, and the microspheres look like waxberries. UV-vis absorption spectra showed that samples within the wavelength range from 0 to 300 nm show strong UV absorption and 10 nm BM-shift, which was highly related to its microstructures. The TEM and high resolution TEM results showed a novel mechanism for fluorinated TiO2 microsphere formation, i.e. its rod-assembled mesoporous microstructures related to the absorption of water molecules on the surface of the microspheres.Keywords: TIO2 MICROSPHERESFLUORINATIONMICROWAVE IRRADIATIONXPS