Effects of N Doping on Structure and Improvement Photocatalytic Properties of Anatase TiO2 Nanoparticles

In order to improve UV and visible lights photocatalytic activities of the pure anatase TiO2, a novel and efficient N-doped TiO2 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 TiO2 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 TiO2, reduces average size of the TiO2 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 TiO2 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-TiO2 photocatalyst shows higher visible photocatalytic activity than the pure TiO2. The optimal N/TiO2 concentration to obtain the highest photocatalytic activity was 2:1 of triethylamine.