Synthesis and characterization of Fe doped TiO2 composite with iron concentration varying from 0 to 7% as a photocatalyst in the photodegradation of methylene orange on UV/visible light irradiation in a closed reactor has been carried out. Synthesis was conducted by the ultrasound method at room temperature using Tetrabutyl titanate and Iron (III) Chloride 6-hydrate as a precursor, followed by thermal treatment at a temperature of 600 oC. The characterizations were performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), FT-IR spectrometry, thermal analysis, UV-Vis diffuse reflectance spectrophotometer, Photoluminescence and Brunauer-Emmett-Teller (BET). XRD spectra revealed that samples crystallized in the anatase phase at 600 °C. The transmission and scanning electron microscopy were used to detect the morphology of synthesized nanoparticles, which sizes changed with the altitude in the doping concentration to 7%. FTIR spectra exhibit broad peaks where anatase phases of TiO2 demonstrate very sharp peaks. In accordance with UV–visible absorption measurements, this diminution of nanoparticles sizes was followed by a decrease in the band gap value from 3.21 eV, for undoped TiO2, to 2.46 eV, for TiO2 doped at 7%. The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. The maximum photoconversion efficiency was 2.5%, which was 6 times the photoconversion efficiency of undoped TiO2. Finally, the prepared materials were used to photocatalyse the decolourization of methylene orange (MO) in aqueous medium as a model compound under the illumination of visible light (λ = 420 nm)

Financial support from Faculty of Science in University of Gabes, Tunisia, Spanish Ministerio de Economía y Competitividad (MINECO-13-MAT2013-40950-R, and FPI grant BES2011-046948 to MSM.A.) and Gobierno del Principado de Asturias (GRUPIN14-060) are acknowledged