Photocatalytic degradation properties of V-doped TiO to automobile exhaust.

To improve the photocatalytic degradation properties of titanium dioxide (TiO) used as raw materials for purifying automobile exhaust (AE), the vanadium (V)-doped TiO samples were prepared. The photocatalytic degradation efficiencies of V-doped TiO to each component in AE were evaluated under ultraviolet (UV) and visible light irradiation, respectively. Results indicated that the photocatalytic activity of V-doped TiO to AE was higher than that of pure TiO, and the optimal V dopant content of TiO was 1.0% under UV light irradiation. The degradation efficiencies of V-doped TiO to NOx and HC were higher than those to CO and CO in AE because of the reversible reaction between CO and CO. In addition, it was found that the photocatalytic degradation efficiencies of V-doped TiO to each component in AE were also increased under visible light irradiation. The V-doped TiO also showed higher degradation efficiencies to NOx and HC than those to CO and CO under visible light irradiation. The V doped TiO presented higher photocatalytic activity to CO than that to CO, but the reversible reaction between CO and CO was not found under visible light irradiation. The photocatalytic reactions of pure and V-doped TiO samples to each component in AE followed the first order kinetic pathway under the two light irradiations. It is concluded that the V doping is a feasible method to improve the photocatalytic degradation properties of TiO to AE for air purification, developing a sustainable environmental purification technology based on TiO materials.