Comparative assessment of the efficiency of Fe-doped TiO2 prepared by two doping methods and photocatalytic degradation of phenol in domestic water suspensions

Fe-doped TiO2 particles responding to visible light were synthesized by impregnation and calcination method using TiO2 particle and Ti element, respectively. The optical and the chemical properties were characterized by measuring the X-ray diffraction (XRD) and UV-visible spectroscopy. The onset of absorption shifted to longer wavelengths on doping TiO2 by the calcination process, which showed a better response as compared to the impregnation method. The photocatalytic reactivity was evaluated by the degradation of phenol with impregnated Fe-doped (0.5% w/w in Fe) and calcined Fe-doped (FexTi1-xO2, x = 0.005 (Fe/Ti molar ratio)) TiO2 separately in distilled and tap water. The characterization results have confirmed the advanced possibility of correlation between photoactivity and the special property of sulfur-containing calcined Fe-doped TiO2. In case of the coagulation of the undoped A-I and the Fe-doped B-I, the photoactivity showed a decrease due to the presence of natural electrolytes and due to the high pH of tap water, whereas in the case of the coagulation of calcined Fe-doped TiO2 prepared from sulfides (FexTiS2), the photoactivity showed an increase. In this study, highest catalytic activity was found to be strongly dependent both on catalyst structure and on the type of water used. (C) 2007 NIMS and Elsevier Ltd. All rights reserved.