Preparation and Nonstoichiometric Property of wide Compositional Fe(III)-doped TiO₂ (anatase)

Fe(III)-doped TiO₂ (anatase) was prepared by the oxidation of Fe_xTiS₂. Two calcination methods were used to oxidize Fe_xTiS₂. In the first, sulfide was calcined in air at a given temperature for 2 h. In the second method, the sulfide was heated in air at a finite heating rate (2.5 K/min) and then held at a constant temperature for 2 h. Fe(III) ions completely dissolved into TiO₂ (anatase), forming Fe(III)-doped TiO₂ (anatase), in the composition range of 0 ⩽ Fe/Ti ⩽ 0.3 (mole ratio). The properties of the obtained oxide depended on the oxidation method of Fe_xTiS₂. The electronic property and the valence stage of the Fe(III)-doped TiO₂ (anatase) were examined. The activation energy of electronic conduction decreased with an increase of the doped amount of Fe(III) ions. The x-ray photoelectron spectroscopy result showed that the electron density on the Ti ion in the Fe(III)-doped TiO₂ (anatase) was decreased by the Fe(III) doping.