Characterization of Visible Light Response N-F Codoped TiO2 Photocatalyst Prepared by Acid Catalyzed Hydrolysis

N-F codoped TiO2 (TONF) photocatalysts were prepared using acid catalyzed hydrolysis method from mixed aqueous solution of TiCl4 and NH4F. The photocatalytic activity of the TONF was evaluated through the degradation of phenol under both visible and UV light irradiation. X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), scanning electron microscope (SEM), and N2 adsorption isotherm were used to characterize the obtained powders. The results showed that N-F codoped TiO2 exhibited significant improvement of visible light catalytic activity. N-F codoping could improve dispersion of TiO2, inhibit particle size agglomeration, and retard phase transformation. Doped N could extend the light response of TiO2 to visible light region. In addition, narrower band gap formed by F-doping was beneficial to the high visible light photocatalytic activity.