Heterogeneous photo-Fenton degradation of methyl orange by Fe₂O₃/TiO₂ nanoparticles under visible light

A novel heterogeneous photo-Fenton catalyst Fe₂O₃/TiO₂ nanoparticle was successfully prepared by sol-gel method and characterized by X-ray diffraction (XRD), UV–vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), Photoluminescence spectra (PL) and porosimetry analysis. The characterization results showed that the nano-sized Fe₂O₃ particles appeared on the TiO₂ support and the Fe₂O₃/TiO₂ nanoparticle exhibited enhanced absorption in the broad visible-light region together with an apparent red shift in the optical absorption edge. The XPS results revealed that the presence of Ti⁴⁺ and Fe³⁺ in Fe₂O₃/TiO₂ materials. The activity of heterogeneous photo-Fenton catalyst Fe₂O₃/TiO₂ combined with the photocatalytic and photo-Fenton was assayed in the degradation of methyl orange (MO) in the presence of visible light and H₂O₂. The results showed that the heterogeneous photo-Fenton was much faster and higher removal of methyl orange than the photocatalytic degradation alone. The mineralization of the organic pollutant was investigated by total organic carbon (TOC) measurements. The Fe₂O₃/TiO₂ + H₂O₂ showed the highest TOC mineralization of MO. All these results indicate the possibility of the practical application of this photocatalyst for water treatment.