Influence of Fe3+ ions on the optical properties and photocatalytic ability of spin coated Fe3+ doped brookite TiO2 thin films

Abstract

The spin coating process has been used to deposit pure and Fe3+ doped brookite titania films onto glass substrates. In essence, such as films annealed at 500 °C are found to be orthorhombic crystal structure with brookite phase. X-ray diffractometer measurements revealed that Fe ions are incorporated into cation sites of TiO2. The crystallite size reduces with the doping of Fe3+ ions. The scanning electron microscope images show highly uniform, crack free films and the particles size is found to be within the range of 150–200 nm. Energy-dispersive x-ray spectroscopy analysis Fe3+ doped TiO2 films confirmed good stoichiometry of chemical compositions. The Raman spectra of brookite TiO2 exhibit a very strong characteristic band at 153cm−1. The optical band gap was found to be declined from 3.08 eV to 2.54 eV with adding the Fe ions into TiO2 matrix. The EPR studies approve incorporation of Fe3+ in the crystal lattice of brookite by substituting Ti4+ and generation of defects, and Ti3+ states. Photocatalytic ability of films has been studied by degradation of methyl orange solution under illumination of visible light. The 7% Fe doped brookite film was exhibited high catalytic activity compared to other pure and doped films.