A simple route was developed for the synthesis of highly crystalline N-doped TiO2 nanoparticles under low temperature (i.e. <= 348 K) and ambient pressure, through hydrolysis of titanium-n-butoxide in acidic ethylamine solution. The as-prepared particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) measurement, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectra (DRS), and TG-DSC analysis. The results indicated that N atoms had got incorporated into TiO2 lattices as evidenced by the formation of O-Ti-N bonds. This process occurred under mild condition, i.e. without further calcinations. The N-doped TiO2 particles exhibited large BET surface area. Photocatalytic activity was evaluated by degradation of dye X-3B under artificial sunlight irradiation, and N-doped TiO2. samples showed much higher activity than that of pure TiO2 and P25. (C) 2008 Elsevier B.V. All rights reserved.