The photocatalytic effect contributes to the reduction of atmospheric pollution, mainly on nitrogen oxide (NOx):
-By direct action: Reduction of harmful gaseous substances (nitrogen oxide (NOx) such as Benzene, Toluene, etc.), produced by human activity (Industries, Automobiles, Heating, etc.). Degradation of the macromolecule (NOx) endorsed by the laboratory accord
For indirect action: By destroying pollutants ozone precursors (NOx), with the formation of ozone (O3).