Fabrication, characterization and photocatalytic activity of preferentially oriented TiO₂films

Preferentially oriented anatase TiO2films were uniformly deposited on the surface of stainless steel substrate by a liquid phase deposition (LPD) method at 60 °C using TiF4and H3BO3as precursors. The as-prepared TiO2films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The photocatalytic activity of the as-prepared TiO2films was evaluated by the photocatalytic oxidation of NO in the gaseous phase. It was found that the deposition conditions, such as the precursor concentrations (H3BO3and TiF4), the deposition time and the pH, had an obvious effect on the formation of oriented TiO2films. The prepared TiO2films showed a preferential orientation in the [0 0 1] direction perpendicular to the stainless steel substrate. A formation mechanism was proposed to account for the preferential orientation and textured morphology of the TiO2films. The photocatalytic oxidation of NO indicated that the preferentially oriented TiO2films exhibited an obvious photocatalytic activity without high-temperature calcination.