One-pot synthesis and photocatalytic activity of Fe-doped TiO2 films with anatase–rutile nanojunction prepared by plasma electrolytic oxidation

A novel one-pot low temperature preparation of Fe-doped anatase–rutile TiO2 (Fe-TiO2) films is demonstrated using plasma electrolytic oxidation (PEO). Pale yellow TiO2 films are obtained by PEO treatment of Ti metals in the electrolyte dispersing TiO2 and Fe2O3 particles. The oxidized layer on Ti metal have a sponge-like structure with thickness and pore size of 10 and 0.1–1 μm, respectively. Investigation by X-ray diffraction, X-ray photoelectron spectroscopy, and UV–Vis absorption spectroscopy all indicate that dissolved Fe3+ ions in the strong acidic electrolyte are doped into the TiO2 structure during PEO. The photocatalytic activity of Fe-TiO2 samples was investigated by studying the photocatalytic decomposition of acetaldehyde. Fe-TiO2 samples doped with optimum Fe content show visible light photocatalytic activity and further increased photocatalytic activity under UV illumination compared with that of pure TiO2 films.