Study on Photo catalytic Self-Cleaning concrete using Titanium Dioxide
CONCEPT
Photo catalytic effect of TiO2 is the underlying principle behind the self-cleaning concrete.
Using this additive concrete structure will ideally behave like a tree absorbing gaseous pollutants
from atmosphere and releasing relatively harmless compound back into the environment. Also
structure is able to replenish its external finish by virtue of the additives ability to carry out self
cleaning by its reaction with compounds present in the environment that are responsible for
surface finish degradation.
It is a natural phenomenon whereby a substance, called a photo catalyst, alters the speed of
a chemical reaction through the action of light. By exploiting the energy of light, photo catalysts
induce the formation of strongly oxidizing reagents which can decompose some organic and
inorganic substances present in the atmosphere. Photo catalysis is, therefore, an accelerator for
oxidization processes that already exist in nature. Indeed, it promotes faster decomposition of
pollutants and prevents them from accumulating on the surfaces. The worsening of the level of
pollution in urban areas has recently driven research towards the application of the capability of
removing harmful substances present in the atmosphere. Photo catalysis, therefore, makes an
effective contribution to improving air quality.
Since then, some of the major applications have been the degradation of organic pollutants in
water, the purification of air and the photo catalytic antibacterial effect in so-called “self cleaning”
building materials . Photo catalytic oxidization takes place on the surface of the photocatalyst
under ultra violet (UV) light. A photon of light is absorbed by the TiO2, which starts a chemical
reaction by producing an electron hole pair. This electron hole pair can then further produce
hydroxyl radicals. These hydroxyl radicals are the key behind the self cleaning of the
concrete. Two phenomena occur as a result of these factors; one is the photo-induced redox
reaction of absorbed substances, the other is the photo-induced superhydrophilicity. The photo
1
Dept. of Civil Engineering, SIMAT Vavanoor
CONCEPT
Photo catalytic effect of TiO2 is the underlying principle behind the self-cleaning concrete.
Using this additive concrete structure will ideally behave like a tree absorbing gaseous pollutants
from atmosphere and releasing relatively harmless compound back into the environment. Also
structure is able to replenish its external finish by virtue of the additives ability to carry out self
cleaning by its reaction with compounds present in the environment that are responsible for
surface finish degradation.
It is a natural phenomenon whereby a substance, called a photo catalyst, alters the speed of
a chemical reaction through the action of light. By exploiting the energy of light, photo catalysts
induce the formation of strongly oxidizing reagents which can decompose some organic and
inorganic substances present in the atmosphere. Photo catalysis is, therefore, an accelerator for
oxidization processes that already exist in nature. Indeed, it promotes faster decomposition of
pollutants and prevents them from accumulating on the surfaces. The worsening of the level of
pollution in urban areas has recently driven research towards the application of the capability of
removing harmful substances present in the atmosphere. Photo catalysis, therefore, makes an
effective contribution to improving air quality.
Since then, some of the major applications have been the degradation of organic pollutants in
water, the purification of air and the photo catalytic antibacterial effect in so-called “self cleaning”
building materials . Photo catalytic oxidization takes place on the surface of the photocatalyst
under ultra violet (UV) light. A photon of light is absorbed by the TiO2, which starts a chemical
reaction by producing an electron hole pair. This electron hole pair can then further produce
hydroxyl radicals. These hydroxyl radicals are the key behind the self cleaning of the
concrete. Two phenomena occur as a result of these factors; one is the photo-induced redox
reaction of absorbed substances, the other is the photo-induced superhydrophilicity. The photo
1
Dept. of Civil Engineering, SIMAT Vavanoor
