Characterization of metal doped-titanium dioxide and behaviors on photocatalytic oxidation of nitrogen oxides

A series of nanosized ion-doped TiO2 catalysts with different ion content (between 0.1 at.% and 1.0 at.%) have been prepared by wet impregnation method and investigated with respect to their behavior for UV photocatalytic oxidation of nitric oxide. The catalytic activity was correlated with structural, electronic and surface examinations of the catalysts using X-ray diffraction analysis (XRD), ultraviolet-visible (UV-Vis) absorption spectroscopy, transmission electron microscopy (TEM), energy disperse spectrometer (EDS) and high resolution-transmission electron microscopy (HR-TEM) techniques. An enhancement of the photocatalytic activity was observed for Zn2+ doping catalyst ranged from 0.1 at.% to 1.0 at.% which was attributed to the lengthened lifetime of electrons and holes. The improvement in photocatalytic activity could be also observed with the low doping concentration of Cr3+ (0.1 at.%). However, the doping of Fe3+,Mo6+,Mn2+ and the high doping concentration of Cr3+ had no contribution to photocatalytic activity of nitric oxide.