Solvothermal synthesis of N-doped TiO2 nanoparticles using different nitrogen sources, and their photocatalytic activity for degradation of benzene

Abstract

Anatase-brookite mixed-phase N-doped TiO2 (N-TiO2) nanoparticles were synthesized through a solvothermal method using different nitrogen sources. The resulting samples were characterized by X-ray diffraction, specific surface area measurement, X-ray photoelectron spectroscopy, and standard and high-resolution transmission electron microscopy. The effects of the different nitrogen sources on phase composition, particle size, microstructure, and specific surface area are investigated. The photocatalytic activity of the TiO2 samples was evaluated through photocatalytic degradation of gaseous benzene under UV-light irradiation. N-TiO2 prepared using hydrazine hydrate achieved the highest photocatalytic performance in all the samples studied (including the commercial P25). Different intermediates during the photocatalytic degradation of benzene over HNT were identified by GC-MS analysis. A detailed reaction mechanism was proposed to explain their formation as intermediates in the reaction. Moreover, the photocatalytic activity of the nanoparticles remained almost unchanged after 15 gaseous-benzene degradation test cycles.