Applied Surface Science, Vol.473, 343-351, 2019
Nitrogen doped iron titanate films: photoelectrochemical, electrocatalytic, photocatalytic and structural features
Nitrogen doped nanosized iron titanate films have been obtained by fast, low cost and precisely controllable synthesis procedure and characterized by XRD, TEM, EPR, optical spectroscopy, photoelectrochemical, electrocatalytic and photocatalytic approaches. The nitrogen doped iron titanate films are crystallized to pseudobrookite (Fe2TiO5) and landauite (Fe2Ti2O7), as revealed by XRD. It is found that nitrogen doping led to stabilization of iron titanate phases at higher temperature preventing their transformation to TiO2 and Fe2O3. The bandgap energy values and the position of the flatband potentials of Fe2TiO5 and Fe2Ti2O7 have been obtained from photoelectrochemical data. Anodic shift of the flatband potentials and the decrease of bandgap energy are noted for iron contained materials. All the iron titanate films exhibit the lower photocurrent quantum yield in UV region compare to iron free films, while the significant photocurrent of the former electrodes has been observed at the lower energy light. The iron titanate films synthesized at certain conditions showed the high photocatalytic activity in the reduction and oxidation processes under both UV and visible light. Adsorption of the pollutant species is established to be considerable for the photocatalytic processes. The influence of doping on the electrocatalytic activity of the films in the processes of oxygen reduction is shown.
Keywords:Nitrogen doping;Pseudobrookite;Landauite;Flatband potentials;Photocurrent quantum yield;Photocatalysis