There are many material that has been in use for roofing and tile has been the most. Tile has provided the unique combination of form and function, being both aesthetically pleasing and highly durable.
Currently, the World Health Organization (WHO) states that 92% of the world’s population live in areas where at least one of the air quality standards is not met. The WHO estimates 88% of those affected by health problems due to pollution. An average human being consumes about 10,000 to 20,000 litres of air every day; there is an intake of 7-14 litres of air by us in a minute.
Smog is a combination of smoke and fog. When certain amount of fuel is burnt for a productive or consumptive purpose, it gives rise to nitrogen oxide and volatile compounds, these chemicals react with sunlight giving rise to smog that is one of the most hazardous air pollution phenomenon. Smog occurrence depends directly on the temperature. Temperature inversions are situations when warm air does not rise instead stays near the ground. During situations of temperature inversions if the wind is calm, smog may get trapped and remain over a place for days.
Smog-eating tile integrates titanium dioxide into micro mortar coating over the body of the tile.Smog eating tile oxidizes harmful NOx molecules that releases from vehicles and other sources thus making air safer to breathe.
The coating of the tile contain a photo catalyst that is activated by daylight that helps converting nitrous oxides into calcium nitrates. High potential photon allow electron to jump from lower valence band to higher valence band. Minimum energy required for this is 3.2 electron volts. The promoted electron used to reduce one molecule in a redox reaction, while the positively charged hole is used to oxidize the other molecule.
When this tile is exposed to light, the photocatalyst on the surface speeds up the oxidation process to reduce pollution. Thus after a period of time, when it rains , the small quantity of organic residue is washed off the roof and the cycle goes on.