Influence of Fe Doping on the Crystal Structure and Optical Properties of Mechanically Activated SrTiO3 Powders

Iron-doped strontium-titanate (SrTiO3) powders with various iron(III) oxide (Fe2O3) weight percentages (1.5, 3 and 6 wt%) were prepared by a solid-state method in the presence of mechanical activation (10, 30 and 120 min). A systematic investigation by XRD, SEM and Raman spectroscopy has been undertaken to evaluate the role of dopant on the microstructural and morphological study of the perovskite oxide obtained. The optical properties of the different iron-doped and activated Fe-SrTiO3 powders have been also evaluated. The results demonstrated that Fe has been substituted into the lattice and surface layers of particles of SrTiO3 powders and the absorption edge shifted to higher wavelength values with increasing activation time and dopant weight percentage. The lowest value of the band gap (Eg=3.20 eV) was registered for the longest activation (120 min) and the highest weight percentage of dopant (6 wt%). Combining doping with mechanical activation, led to lower values of Eg and that fact could be used in subsequent studies to make Fe-SrTiO3 more suitable photocatalysts.