Effects of Fe-doping on the photocatalytic activity of mesoporous TiO2 powders prepared by an ultrasonic method

Highly photoactive nanocrystalline mesoporous Fe-doped TiO2 powders were prepared by the ultrasonic-induced hydrolysis reaction of tetrabutyl titanate (Ti(OC4H9)4) in a ferric nitrate aqueous solution (pH 5) without using any templates or surfactants. The as-prepared samples were characterized by thermogravimetry and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), N2 adsorption-desorption measurements, UV-visible adsorbance spectra (UV-vis) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities were evaluated by the photocatalytic oxidation of acetone in air. The results showed that all the Fe-doped TiO2 samples prepared by ultrasonic methods were mesoporous nanocrystalline. A small amount of Fe3+ ions in TiO2 powders could obviously enhance their photocatalytic activity. The photocatalytic activity of Fe-doped TiO2 powders prepared by this method and calcined at 400 °C exceeded that of Degussa P25 (P25) by a factor of more than two times at an optimal atomic ratio of Fe to Ti of 0.25. The high activities of the Fe-doped TiO2 powders could be attributed to the results of the synergetic effects of Fe-doping, large BET specific surface area and small crystallite size.