It has developed building materials that with the addition of a light titanium dioxide layer these are capable of diminishing the pollution. The contamination that exists in the lower layers of the atmosphere in the cities, is generated by oil and particles floating in the air due to poor combustion in cars, industry and heating.
More than two decades ago began to conduct scientific studies on the photocatalysis. One aspect that presented the greatest potential is the application of photocatalysis to environmental cleanup.
The photocatalysis and the dioxide of titanium:
The photocatalysis is a chemical reaction that is produced in the surface of an element caused by the energy of the light. Titanium dioxide is one of the basic materials used in everyday life. It is used in variety of paints, cosmetics and even in the manufacture of certain food materials. Naturally, the type of titanium dioxide used for the manufacture of a pigment is not the same as that used in a photocatalytic process.
Titanium dioxide is a chemically active semiconductor when it affects the energy of light. However, this property of photoactivity was considered a problem and should be regulated when it was used as white pigment. The photoactivity of titanium dioxide tends to break down organic materials in contact with it, leading to the bleaching of the paintings.
On the other hand, the phenomenon of titanium dioxide photocatalyst is of fundamental importance in the decomposition of materials, so you get used to the fight against pollution.
What happens when titanium dioxide is exposed to light is that it leads to destruction of external agents, such as snuff smoke, oil and bacteria and viruses, but this happens only under certain conditions. The use of photocatalysis for cleaning the outside air requires the use of energy from solar radiation. On the other hand, it is necessary that the catalysis takes place on flat surfaces, so that they can be fully exposed to sunlight.
The fight against pollution:
The photocatalyst of the dioxide of titanium has the capacity to eliminate the oxides of nitrogen (NOx). What occurs in that reaction of photocatalysis is that the monoxide of nitrogen oxidizes when the catalysis that is to say the dioxide of titanium, is exposed to the light, being becoming dioxide of nitrogen and finally in nitric acid. It has been shown that other particles, like the dioxide of sulfur, also they can be cleaned.
A problem that could arise is that some of the decomposition products remain on the surface of the material with titanium dioxide, for example in the case of nitrogen oxides or sulfur compounds accumulate on the surface as nitric or sulfuric acid and necessary to evacuate them, so you can continue the reaction.
If the pollution due to composed of carbon, these are break down completely in dioxide of carbon. This indoor applications for interiors can suppose a serious problem, fortunately it is not in the case of exterior applications, since an effect of wash with the rainwater is produced, that does that the material continue with its activity.
Building Materials:
This process applies to building materials in order to combat environmental pollution. They have therefore developed ceramic tiles and concrete, tiles and other products cement and concrete and even glass, but in this case they need to be covered with a film.
Applied to concrete results in a dual functionality, the self-cleaning concrete surface and otherwise improving the environmental pollution by reducing pollutants. Currently, you can find applications of this research, successfully operating in various countries such as Japan or Australia.
