N-doped TiO2 nanoparticles were prepared by using 10 and 20 alkyl and alcohol amines [n-propylamine (nPRYL), ethanolamine (ETOH), propanolamine (PROH), diethylamine (DETYL), dipropylamine (DPRYL), diethanolamine (DETOH), and ammonium hydroxide (NH4OH)] as nitrogen sources through microwave and hydrothermal growth (HT) methods. Characterization of the nanoparticles was done by X-ray diffraction, scanning electron microscopy, ultraviolet visible absorption spectra, X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy and BET analysis techniques. Nitrogen species in TiO2 lattice were interstitial impurities. Nitrogen content of the particles depended on the preparation conditions and structural differences of nitrogen sources. Photocatalytic degradation of methylene blue was carried out under Xenon lamp irradiation. N-doped TiO2 nanoparticles exhibited higher photocatalytic activity, compared to undoped ones. Acidity differences of amine sources and irradiation differences of synthetic conditions had an effect on photocatalytic activity. Although N doping into TiO2 lattice was the least effective in the particle prepared by the use of nPRYL as the amine source and HT as the synthetic condition, its photocatalytic activity was slightly better compared to others. (c) 2010 Elsevier Ltd. All rights reserved.