Visible light catalysis of rhodamine B using nanostructured Fe2O3, TiO2 and TiO2/Fe2O3 thin films

• Preparation of nanostructured TiO2/Fe2O3 multilayered films.
• Structural and chemical state of the elements by XPS.
• Photocatalytic oxidation of Rh B under visible light.
• Reaction kinetics and mineralization of Rh B.

The Fe2O3, TiO2 and TiO2/Fe2O3 composite films are deposited using spray pyrolysis method onto glass and FTO coated substrates. The structural, morphological, optical and photocatalytic properties of Fe2O3, TiO2 and TiO2/Fe2O3 thin films are studied. XRD analysis confirms that films are polycrystalline with rhombohedral and tetragonal crystal structures for Fe2O3 and TiO2 respectively. The photocatalytic activity was tested for the degradation of Rhrodamine B (Rh B) in aqueous medium. The rate constant (−k) was evaluated as a function of the initial concentration of species. Substantial reduction in concentrations of organic species was observed from COD and TOC analysis. Photocatalytic degradation effect is relatively higher in case of the TiO2/Fe2O3 than TiO2 and Fe2O3 thin film photoelectrodes in the degradation of Rh B and 98% removal efficiency of Rh B is obtained after 20 min. The photocatalytic experimental results indicate that TiO2/α-Fe2O3 photoelectrode is promising material for removing of water pollutants.