Photocatalytic Degradation of Nitrogen Oxides on Titania under UV and Visible Light Irradiation and Application in Outdoor Air Purification

The ultraviolet and visible light activated titanium dioxide was synthesized and employed in the photocatalytic oxidation of NO. Sol-gel process by using tetra-n-butyl orthotitanate and ethanol to synthesize mixed-crystal (anatase and brookite) titanium dioxide were carried out under acid catalyzed condition. Platinum was loaded with impregnation method on the surface of titanium dioxide to modify the property. The prepared photocatalysts were activated in the degradation of NOx under ultraviolet and visible light, respectively. The experimental results showed that near 40 % removal of NO could be obtained in a flow type reaction system under irradiation of visible light. Furthermore, an outdoor air purification device with photocatalyst was developed under the sunlight irradiation. The result of outdoor test showed high potential application of photocatalyst in the removal of NOx contaminants