Nanostructured TiO2 and Fe-doped TiO2 thin films with high transparency were deposited on glass
substrate through ultrasonic-assisted spray pyrolysis technique and were used in the visible light
photocatalytic degradation ofMBdye. The resulting thin films were characterized by scanning
electron microscopy (SEM), Raman spectroscopy, photoluminescence spectroscopy, x-ray diffraction
(XRD), and UV-visible absorption spectroscopy techniques. Based on Raman spectroscopy results,
both of the TiO2 and Fe-doped TiO2 films have anatase crystal structure, however, because of the
insertion of Fe in the structure of TiO2 some point defects and oxygen vacancies are formed in the Fedoped
TiO2 thin film. Presence of Fe in the structure of TiO2 decreases the band gap energy of TiO2
and also reduces the electron–hole recombination rate. Decreasing of the electron–hole recombination
rate and band gap energy result in the enhancement of the visible light photocatalytic activity of
the Fe-doped TiO2 thin film.