Abstract: Nanostructured N-doped TiO2 thin films were obtained by anodic oxidation of titanium nitride films, which were prepared by electrophoretic deposition (EPD) at room temperature on titanium foils. The resultanted thin films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and photoelectrochemical methods. XRD patterns showed that anatase type TiO2 existed in the thin films after anodic oxidation and annealing at 350 ℃ in air for 1 h. According to XPS residual N atoms partially occupied O atom sites in the TiO2 lattice. A nanostructured surface containing nanosized holes was observed by SEM images of thin films after anodization. The photoelectrochemical response of the N-doped TiO2 thin film was enhanced after anodic oxidation and annealing treatment. The current density under visible light at 0 V was 2.325 μA·cm-2 while the current density of thin films only prepared after annealing using the same conditions was 0.475 μA·cm-2. The high photoelectrochemical response from visible light of N-doped TiO2 thin films resulted from their nanostructured surfaces that were created after anodic oxidation.

Key words: Electrophoretic deposition, Titanium nitride, Anodic oxidation, Nitrogen-doped dioxide titanium, Photoelectrochemistry