Synthesis and photocatalytic activity of nanocrystalline TiO_2 co-doped with nitrogen and cobalt(II)

摘要

Nitrogen-modified cobalt-doped TiO_2 materials were successfully prepared via a modified sol-gel method. The structure and properties of the catalysts were characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM, ultraviolet-visible light diffuse reflectance spectra (UV-Vis DRS), N_2 adsorption-desorption isotherms, and energy-dispersive X-ray spectroscopy. The XRD patterns of the pure and co-doped TiO_2 samples indicate that the predominant phase was anatase. The average grain size obtained from TEM was approximately 10 nm. The Brunauer-Emmett-Teller analysis results indicate that the specific surface area was 77.7 m~2 g~(-1). The UV-Vis DRS results for the co-doped sample reveal an absorption edge that had been red-shifted to 500 nm. The photocatalytic activities of the samples were evaluated through photodegradation of papermaking wastewater under UV and visible light irradiation. Compared with the cobalt-doped TiO_2 sample and Degussa P25, the 3 mol% N-doped mesoporous N/Co-TiO_2 photocatalyst exhibited the highest photocatalytic activity, which can be ascribed to the synergistic effect of the N and Co co-doping.