Photocatalytic activity and formation of oxygen vacancies in cation doped anatase TiO2 nanoparticles

We report the influence of iron doping on structure, stoichiometry, and photocatalytic efficiency of single phase anatase TiO2 nanoparticles which were synthesized via the sol gel technique. The XPS and FTIR results reveal the formation of oxygen vacancies and Ti3+ defects following doping with iron which was further confirmed by PL studies. XRD and TEM investigations indicate that the phase structure of TiO2 nanoparticles is preserved after incorporation of iron to the crystallographic lattice. XRD peak shift and broadening, observed in the doped nanoparticles, were attributed to the formation of point defects and the resulted strains. Photocatalytic activity of the samples was examined through measuring the decomposition rate of rhodamine B under ultraviolet illumination. It was found that Fe-doping significantly improves the photocatalytic activity of anatase TiO2. We envisage that a more effective use of the UV photon energy, higher charge carrier mobility, and suppressed charge recombination due to the point defects are the primary reasons behind the enhanced photocatalytic activity.