Fenton-like oxidation of azo dye using mesoporous Fe/TiO2 prepared by microwave-assisted hydrothermal process

Abstract

Fe-doped TiO2 photocatalysts with different content of Fe (0.5, 1.6, 3.4 and 6.4%) were synthesized by the microwave-hydrothermal method and characterized by XRD, N2 physisorption at 77 K and DRS. The characterization showed that Fe ions are highly dispersed in the TiO2 lattice. It was found that all the synthesized catalysts had the mesoporous structure and Fe doping increased BET surface areas. The UV-Vis study showed that the absorption spectra shifted to a longer wavelength (red shift) with an increase in the dopant concentration. The photocatalytic activity of the samples was evaluated by the decolorization of textile dye Reactive Blue 52 (RB) in aqueous solutions under sun-like radiation in the presence of H2O2 (heterogeneous photo-Fenton process). The photocatalyst with 3.4% Fe was found to be the most efficient with H2O2. The effect of the initial pH of the dye solution was assessed and dissolution of iron ions was studied, as a function of pH value. It was concluded that decolorization is more favorable in acidic pH and when pH >4, the releasing of Fe ions in solution was negligible. Photocatalytic degradation of 4-chlorophenol (4-CP) was investigated under the optimal conditions and proved that our catalyst was capable to degrade colorless pollutants.