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Photo-Catalysis
is defined as
"acceleration by the presence of as catalyst". A catalyst does
not change in itself or being consumed in the chemical reaction.
This definition includes photosensitization, a process by which
a photochemical alteration occurs in one molecular entity as a
result of initial absorption of radiation by another molecular
entity called the photosensitized.
Chlorophyll of plants is a type
of photocatalyst. Photocatalysis compared to photosynthesis, in
which chlorophyll captures sunlight to turn water and carbon
dioxide into oxygen and glucose, photocatalysis creates strong
oxidation agent to breakdown any organic matter to carbon
dioxide and water in the presence of photocatalyst, light and
water.
Titanium Dioxide structured in
anatase form is the most common photocatalyst. It has the
following advantage:
- Cost Effective
- High photocatalytic effect
- None-Toxic
Titanium dioxide, also known as
titania, is the naturally occurring oxide of titanium, chemical
formula TiO2. Approved by the food testing laboratory of the
United States Food and Drug Administration (FDA), Titanium
Dioxide is considered a safe substance and harmless to human. It
is commonly used in paint, printing ink, plastics, paper,
synthetic fibers, rubber, condensers, painting colors and
crayons, ceramics, electronic components along with food and
cosmetics. Many studies have been published on the use of
titanium dioxide as a photocatalyst for the decomposition of
organic compounds. After illuminated by light, titanium dioxide
produces hydroxyl radicals, which react with the organic matters
in the air to form non-toxic inorganic matters.
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