The Principle of Photocatalytic Air Purifier and Its Application in Air Purification
1、 The principle of photocatalytic air purifier
Photocatalytic air purifier is a device that uses photocatalytic reactions to purify air. Its working principle is based on photocatalysis, which includes two main processes: photolysis and catalytic reaction.
Firstly, the photolysis process. The air purifier is equipped with photocatalyst materials inside, usually using titanium dioxide (TiO2) as the main catalyst. When light strikes the surface of the catalyst, it absorbs light energy and forms electron hole pairs. Among them, electrons and holes are highly active.
Secondly, the catalytic reaction process. The electron and hole pairs generated by photoexcitation will participate in a series of catalytic reactions. Holes have strong oxidizing properties and can oxidize pollutants in the air, such as organic matter, bacteria, viruses, etc. And electrons can reduce oxygen molecules, producing reactive oxygen species such as hydroxyl radicals (· OH), thereby further decomposing organic pollutants.
Through photocatalytic reactions, photocatalytic air purifiers can efficiently decompose and eliminate harmful substances in the air, improving air quality.
2、 Application of photocatalysis in air purification
Photocatalytic technology has broad application prospects in the field of air purification.
VOCs removal: Volatile organic compounds (VOCs) are common pollutants in the air and have high toxicity. Photocatalytic air purifiers can decompose VOCs into harmless substances through photocatalytic reactions, effectively reducing indoor air pollution.
Virus and bacterial elimination: The catalytic reaction of photocatalytic air purifiers can also destroy the membrane structure of microorganisms such as viruses and bacteria, causing them to become inactive. This is of great significance for preventing airborne diseases, especially in promoting the resistance to viral respiratory infections.
Odor removal: Photocatalytic air purifiers can quickly degrade odorous substances such as smoke, cooking odors, pet odors, etc. By effectively removing odors, they provide a fresh and comfortable indoor environment.
It should be noted that there are still some limitations in the practical use of photocatalytic air purifiers. For example, photocatalytic reactions require a certain intensity and wavelength of light, so sufficient light sources should be ensured in indoor environments. In addition, large-scale photocatalytic equipment may be required for the treatment of large amounts of air.
In summary, photocatalytic air purifiers decompose harmful substances through photocatalytic reactions and are widely used in VOCs removal, virus and bacteria removal, and odor removal, providing an efficient and environmentally friendly solution for improving indoor air quality.
