EFFECTS OF N DOPING ON STRUCTURE AND IMPROVEMENT PHOTOCATALYTIC PROPERTIES OF ANATASE TIO2 NANOPARTICLES

Abstract

In order to improve UV and visible lights photocatalytic activities of the pure anatase TiO 2 , a novel and efficient N-doped TiO 2 photocatalyst was prepared by sol-gel method. N-doped titania is prepared using triethylamine (with difference molar ratios) as the nitrogen source. The crystalline structure, morphology, particle size, absorbance and band-gap and chemical structure of N-doped TiO 2 was characterized by X-ray diffraction , diffuse reflectance spectra , scanning electron microscopy , energy dispersive spectrometry and Fourier transform infrared techniques, respectively. Results indicate that the doping of N, cause absorption edge shifts to the visible light region compare to the pure TiO 2 , reduces average size of the TiO 2 crystallites, enhances desired lattice distortion of Ti, promotes separation of photo-induced electron and hole pair, and thus improves pollutant decomposition under UV and visible lights irradiation. The photocatalytic activities of N-doped TiO 2 nanoparticles were evaluated using the photodegradation of methyl orange (MO) as probe reaction under the irradiation of UV and visible light and it was observed that the N-TiO 2 photocatalyst shows higher visible photocatalytic activity than the pure TiO 2 . The optimal N/TiO 2 concentration to obtain the highest photocatalytic activity was 2:1 of triethylamine