The nanometer particles of two FexOy/TiO2's with high photocatalytic activities were obtained through hydrothermal treatment and impregnation method. The XRD result did not show the peaks assigned to the Fe components (for example Fe2O3, Fe3O4, FeO3, and Fe metal) on the external surface of the anatase structure in the FexOy/TiO2 attained through hydrothermal treatment. This meant that Fe components were well incorporated into the TiO2 anatase structure. In addition, it exhibited uniform anatase structure with particle size of below 50 nm. The FeO3 component on the external surface of the TiO2 anatase structure was identified in the Fe-loaded TiO2 prepared through the impregnation method. In particular, the FT-IR spectroscopy revealed that the FexOy/TiO2 particle attained through hydrothermal treatment had higher hydrophilic property compared to the other catalysts. Together with the Fe component, they absorbed wavelength of above 370 nm. The band slightly shifted to the right without tail broadness, which was the UV absorption of Fe oxide in the FexOy/TiO2 particle attained through hydrothermal method. This meant that Fe components were well inserted into the framework of the TiO2 anatase structure. Despite the red shift in UV-Vis absorption, however, CHCl3 decomposition on the FexOy/TiO2 catalyst was not largely enhanced compared to pure TiO2. (C) 2003 Elsevier B.V. All rights reserved.