Influence of iron doping on the photocatalytic activity of nanocrystalline TiO2 particles fabricated by ultrasound method for enhanced degradation of organic dye

Abstract

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–Vis 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 °C. The characterizations were performed using X-ray diffraction (XRD), transmission electron microscopy, 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 SEM 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–Vis 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 six times the photoconversion efficiency of undoped TiO2. Finally, the prepared materials were used to photocatalyse the decolourization of methylene orange in aqueous medium as a model compound under the illumination of visible light (λ = 420 nm).