Paving Out Pollution
A common whitener helps to clean the air
Inorganic photocatalysts, such as titanium dioxide, have been exploited for the past 10 years. It has shown to be a relatively cheap and effective way of removing organic poison compounds and pollutant gases from both air and aqueous environments.
For the past 10 years, our TPXsol photocatalsyt material has been successfully integrated by cement, concrete manufacturers in the production. The application has also been introduced through application service provider in the retrofit post application environment. These photocatalyst ecological bricks constitutes a promising technique to reduce a number of air contaminants especially at sites with a high level of pollution: highly trafficked canyon streets, road tunnels, the urban environment, etc. Ideally, the photocatalyst, titanium dioxide, is introduced in the top layer of the concrete pavement for best results. In addition, the combination of TiO2 with cement-based products offers some synergistic advantages, as the reaction products can be adsorbed at the surface and subsequently be washed away by rain.
Air pollution in the city caused by industrial smog, emission of the vehicles have raised many concerns. However many cities in Japan are now using our photocatalyst coating on the pedestrian pavement for purifying the city air. Just 25m2 (270ft2) of our photocatalyst coating is equivalent to the air purifying power of one poplar tree. The oxidizing power of TPXsol means that when pollutants such as smog, car exhaust come in contact with the surface, the photocatalyst titanium dioxide coating decomposes them and convert it into harmless byproducts. ( Test method for air purification performance of photocatalytic materials—JIS R1701-1 Corresponding ISO 22197-1 )
EXHAUST POLLUTANT nitric oxide breaks down when sunlight hits the titanium dioxide-coated concrete, releasing reactive oxygen that turns NOx to nitric acid ions. The alkaline concrete neutralizes the ions, which are washed away by rain.