Investigation of the role of iron doping on the structural, optical and photoluminescence properties of sol-gel derived TiO2 nanoparticles

We have synthesized the Fe doped titania (TiO2) nanopowders using sol-gel process. These samples are formed in anatase form of titania as revealed by X-ray diffraction patterns. The UV/Vis absorption spectra exhibit that Fe-doping causes a considerable red shift of the absorption edge. Energy bandgap estimated using Tauc's relation is found be of direct transition nature and Fe doping decreases the bandgap significantly. Raman spectra indicate an anatase structure of tetragonal crystal symmetry that belongs to the space group D4h19. Photoluminescence spectra recorded in ultraviolet and visible regions reveal that Fe doping increases the photocatalytic activity of our samples. FTIR spectra show that characteristic Ti-O band is observed around 680 cm-1 for pure TiO2 sample and on iron doping it shifted to 592 cm-1.