Direct determination of local structure around Fe in anatase TiO2

The local structures around Fe in the Fe-doped anatase TiO2 samples prepared by sol–gel method have been investigated by XAFS technique. The results indicate that for the Fe-doped TiO2 sample with a low Fe content of 1–2 wt%, Fe atoms are incorporated into the lattice of anatase and located at the substitutional sites of Ti atoms. Fe atoms expand the distance of the nearest oxygen atoms and cause local distortion of the anatase lattice. With the increase of the doping Fe content, the second phase of α-Fe2O3 is aggregated. For the 10 wt% Fe-doped TiO2, most of Fe atoms exist in the form of α-Fe2O3.