Walking down a street in central London, a person may suddenly feel that the air quality is quite clean. The sidewalk has been treated with a nanotechnology product containing catalytic properties that break down molecules in harmful pollutant emissions in the air. In Milan (Italy) and Paris (France), there are similar concrete sidewalks that are treated with titanium dioxide (TiO2). According to some experts, the titanium dioxide concrete slabs have reduced pollutants during rush hour by 60 to 70 percent in these two cities.
Japan's Mitsubishi Materials Corporation has developed a paving stone that uses the catalytic properties of TiO2 to remove nitrogen oxides (NOx) from the air. Nitrogen oxides are emitted into the air primarily from the emissions of automobiles and power plants that burn petroleum and coal. The paving stone breaks down nitrogen oxides into more environmental-friendly substances such as nitric acid ions. These ions can then be washed away by rainfall or neutralized by the alkaline composition of the concrete.
Was this article helpful?