Visible light induced photodegradation of organic pollutants on nitrogen and fluorine co-doped TiO_2 photocatalyst

摘要

The nitrogen and fluorine co-doped TiO_2 polycrystalline powder was synthesized by calcinations of the hydrolysis product of tetra-butyl titanate with ammonium fluoride. Nitrogen and fluorine co-doping causes the absorption edge of TiO_2 to shift to a lower energy region. The photocatalytic activity of co-doped TiO_2 with anatase phases was found to be 2.4 times higher than that of the commercial TiO_2 photocatalyst Degussa P25 for phenol decomposition under visible light irradiation. The co-doped TiO_2 powders only contain anatase phases even at 1000 deg C . Apparently, ammonium fluoride added retarded phase transformation of the TiO_2 powders from anatase to rutile. The substitutional fluorine and interstitial nitrogen atoms in co-doped TiO_2 polycrystalline powder were responsible for the vis light response and caused the absorption edge of TiO_2 to shift to a lower energy region.