Environmental Benefit of Photocatalytic Coatings, such as titanium dioxide (TiO2), are suitable for manifold applications due to their potential application for decomposing a great variety of substances and materials in the air, Photocatalytic active coating systems are able to reduce environmental contaminations and to clear surface of various material.
Both the technological and economic importance of photocatalysis has increased considerably over the past decade. Improvements in performance have been strongly correlated to advances in nanotechnology. A variety of applications ranging from anti‐fogging, anti‐microbial and self‐cleaning surfaces, through to water and air purification and solar induced hydrogen production, have been developed and many of these have made their way into commercial products.
1. Sterilization / Anti-Microbial
Photocatalyst does not only kill bacteria cells, but also decompose the cell itself. The titanium dioxide photocatalyst has been found to be more effective than any other antibacterial agent, because the photocatalytic reaction works even when there are cells covering the surface and while the bacteria are actively propagating. The endotoxin produced at the death of cell is also expected to be decomposed by photocatalytic action. Titanium dioxide does not deteriorate and it shows a long-term anti-bacterial effect. Generally speaking, disinfections by titanium oxide is three times stronger than chlorine, and 1.5 times stronger than ozone.
The product of Green Millennium is not registered with the US EPA as a pesticide product and makes no antimicrobial claims to the general public.
2. Deodorizing Effect
On the deodorizing application, the hydroxyl radicals accelerate the breakdown of any Volatile Organic Compounds or VOCs by destroying the molecular bonds. This will help combine the organic gases to form a single molecule that is not harmful to humans thus enhance the air cleaning efficiency. Some of the examples of odor molecules are: Tobacco odor, formaldehyde, nitrogen dioxide, urine and fecal odor, gasoline, and many other hydro carbon molecules in the atmosphere.
Air purifier with Ti02 can prevent smoke and soil, pollen, bacteria, virus and harmful gas as well as seize the free bacteria in the air by filtering percentage of 99.9% with the help of the highly oxidizing effect of photocatalyst(Ti02).
3. Air Purifying Effect
The photocatalytic reactivity of titanium oxides can be applied for the reduction or elimination of polluted compounds in air such as NOx, cigarette smoke, as well as volatile compounds arising from various construction materials. Also, high photocatalytic reactivity can be applied to protect lamp-houses and walls in tunneling, as well as to prevent white tents from becoming sooty and dark. Atmospheric constituents such as chlorofluorocarbons (CFCs) and CFC substitutes, greenhouse gases, and nitrogenous and sulfurous compounds undergo photochemical reactions either directly or indirectly in the presence of sunlight. In a polluted area, these pollutants can eventually be removed.
Most of the exterior walls of buildings become soiled from automotive exhaust fumes, which contain oily components. When the original building materials are coated with a photocatalyst, a protective film of titanium provides the self-cleaning building by becoming antistatic, super oxidative, and hydrophilic. The hydrocarbon from automotive exhaust is oxidized and the dirt on the walls washes away with rainfall, keeping the building exterior clean at all times.
5. Water Purification
Photocatalytic water purification technology creates safe water by utilizing sun’s ultraviolet rays and photocatalysts to react with harmful substances in the water, rendering them harmless. Compared to chlorination or chemical purification, the impact on the environment is minimal, and it provides the advantage of detoxifying the remained harmful substances after chlorination.
Titanium dioxide (TiO2) is one of the most well-known superior photocatalyst. When it is placed in water and exposed to ultraviolet light, the energy of that light is transmitted to the electrons in the titanium dioxide particles, and high-energy electrons (electron excitation) are generated on the surface of particles In addition to purifying toxic metals like arsenic and hexavalent chromium, these high-energy electrons react with oxygen in the water to generate reactive oxygen, purifying bacteria and organic substances. Reactive oxygen is also generated when the surface of photocatalytic particles from which electrons have already been ejected come in contact with water, contributing to the efficiency of the water purifying effect.