A facile method for synthesis of N-doped TiO_2 nanooctahedra,nanoparticles, and nanospheres and enhanced photocatalytic activity

摘要

N-doped TiO_2 nanooctahedra, nanoparticles and nanospheres were successfully synthesized through nitrification of the corresponding TiO_2 nanostructures in the presence of ammonia gas at 700 ℃ for 30 min. The crystal phase and compositions of N-doped TiO_2 samples were confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The product morphology was characterized with scanning microscopy (SEM) and transmission electron microscopy (TEM). UV-vis absorption results show that all the as-synthesized N-doped TiO_2 samples present red-shift absorption up to ~410nm, which can be ascribed to the addition energy level between TiO_2 valence and conducion band. Surface areas of all samples were measured through nitrogen absorption-desorption isothermal. In order to evaluate the photocatalytic activity of N-doped TiO_2 samples, photodecomposition for methyl orange (MO) was performed under UV-vis light irradiation for 30 min, indicating that N-doped TiO_2 nanooctahedra with the exposed {101} crystallized surfaces show good photocatalytic behavior in comparison with other samples.