The principle of photocatalytic reaction was to accelerate the nature’s cleaning and purifying process using light as energy. Discovered in 1960’s, Dr. Fujishima of Japan found titanium metal, after irradiated by light, could break water molecule into oxygen and hydrogen gas. By restructuring titanium dioxide particles in nano-scale, a number of new physical and chemical properties were discovered. One of these newfound effects was photocatalytic oxidation which accelerated the formation of hydroxyl radical, one of the strongest oxidizing agents created by nature. Using energy found in the UV light, photocatalyst titanium dioxide could breakdown numerous organic substances such as oil grime and hydrocarbons from car exhaust and industrial smog, volatile organic compounds found in various building materials and furniture, organic growth such as fungus and mildew
Together photocatalytic decomposition of organic pollutants providing necessary ingredients to produce oxygen via photosynthesis. The net effect is cleaner air. Less atmospheric pollutants , replaced with oxygen.
Titanium oxide attracts the most attention as a major photocatalyst. Why is titanium oxide practically applied among all the substances with photocatalytic features?
Safe Substance: Its effect on human body is small, and it is harmless as it is also used as a coloring agent of foods and cosmetics.
Production Cost: Ores including titanium oxide exist adequately all over the world, therefore this substance is easily acquired.
Photocatalytic Effect: Titanium oxide has a power to be very highly active when it absorbs light energy. <br>That power performs decomposing function and super hydrophilic function.
Insolubility: It is durable against acid and alkali and organic solvents, so it can be applied to various surfaces as a coating .
Transparent Coating: Titanium oxide hardly absorbs visible light, therefore coating is transparent and it can be applied without distracting its design. If applied too heavily it may lighten on materials of dark color
Anatase and brookite forms of TiO2 are photocatalysts.
TiO2 has very high refractive index and excellent UV absorption properties.
TiO2 is commonly used in products such as sunscreen, paint and toothpaste.
Approximately 4 million tons of TiO2 is used worldwide as a white pigment annually.
In recent years, scientists have developed photocatalysts and visible light photocatalysts for enhanced performance in various environments.
TiO2 (titanium dioxide) occurs in nature as rutile, anatase, and brookite minerals.
Photocatalysis was discovered by Japanese scientist Prof. Fujishima in 1967.
Japan is the first country in the world to successfully commercialise photocatalyst products.
Japan is the global leader in photocatalyst technology development, commercialisation, and standardisation.