Sulfated Fe2O3–TiO2 synthesized from ilmenite ore: A visible light active photocatalyst

Sulfated Fe2O3–TiO2 (SFT) was synthesized by treatment of ilmenite ore with sulfuric acid. The presence of sulfated Fe2O3–TiO2 and mixed phases of Fe2O3–TiO2 was confirmed by DRIFT spectra and XRD. The dispersion of sulfate displayed thermal stability up to 500 °C. The adsorption–desorption of pyridine investigated by DRIFT spectra revealed the presence of both Brønsted and Lewis acid sites for the samples calcined up to 500 °C. The DRS/UV–vis spectra showed UV and visible light absorbance for samples calcined up to 900 °C. A band gap value of 2.73 eV is obtained for 500 °C calcined sample. The photocatalytic activity was evaluated by the oxidation of 4-chlorophenol (4-CP) in aqueous medium under UV–vis and visible light irradiation. SFT calcined at 500 °C demonstrated the highest photocatalytic activity. When compared with high surface area sulfated titania (275 m2/g), the photocatalytic activity was greater due to the presence of iron, despite the low surface area of the SFT samples (12–17 m2/g).