Preparation and photo-catalytic activity of Fe---TiO2 thin films prepared by sol–gel dip coating

Abstract

Thin films of iron (Fe) doped titanium dioxide (Fe---TiO2) were prepared on a variety of substrates by using Ti-peroxy sol–gel dip coating method. The surface structure of the film was modified by adding different concentrations of polyethylene glycol (PEG) into the TiO2 sol. Most of the metal ion doped entered TiO2 lattice resulting the shift in optical absorption edge towards visible side. Addition of PEG alters the surface morphology and structure of the films. The increase in concentration of PEG increases the number and size of the pores on surface of the film by decomposition of PEG when the films are subjected to heat treatment. The adsorbed hydroxyl content of such porous films is found to increase with amount of PEG added. Photo-catalytic properties of the surface modified and Fe ion doped TiO2 catalyst was investigated by degradation of methyl orange in sunlight. The photo-catalytic activity of the PEG added Fe-TiO2 catalyst was enhanced by 2–2.5 times than undoped TiO2.