Abstract: The N-doped visible-light response nanosize TiO2 photocatalyst was prepared using the acid-catalyzed hydrolysis method followed by calcination in an NH3/N2 atmosphere. The photocatalytic activity of the prepared N-doped TiO2 for phenol degradation was investigated under visible and UV light irradiation, respectively. X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and N2 adsorption were used to characterize the catalyst. The results showed that the N-doped TiO2 catalyst displayed obvious photocatalytic activity under visible light irradiation. The N-doped TiO2[KG20x] catalyst calcined at 500 ℃ for 5 h exhibited the highest activity in both UV and visible light regions. N-doping showed little effect on the crystalline structure, surface area, and crystal size of TiO2. The Ti-O-N bond formed on the surface of the catalyst could extend the absorption edge to the visible light region (490-550 nm) and also benefit the photocatalytic acitivity of TiO2 under UV irradiation. The newly formed Ti-O-N bonds and the reduced agglomeration of the single crystals were mainly responsible for the high activity of the N-doped TiO2 in both UV and visible light regions.

Key words: titania, nitrogen, doping, visible light, photocatalyst, phenol, degradation