A photocatalysis air purifier is a device that uses photocatalytic oxidation technology to purify indoor air. It uses a photocatalyst and UV light to produce oxidizing agents that can destroy organic pollutants in the air. The purified air is then released back into the room. They can be effective at removing many common indoor pollutants, but may not be as effective at removing larger particles such as dust and pollen... Overall, do they really keep their promises? In this article, we analyse this air purification technology.
Photocatalysis is the decomposition and the degradation of pollutants through the use of light rays on the surface of a catalyst, generally titanium dioxide. It can eliminate VOCs, inorganic pollutants and microorganisms. The process results in water and carbon dioxide.
Most photocatalysis air purifier manufacturers assert that their air purifiers eliminate 99% of all VOCs, PAHs, viruses, and bacteria up to a size of 0,01 µm. There is an accumulation of research findings conducted in laboratories that confirm the depolluting properties of this technology. But tests under real-life conditions call into question that efficiency. According to the ADEME, photocatalysis is efficient only under certain conditions. Experiments reveal performance gaps depending on mixtures of air pollutants and airflows.
Under real-life conditions, photocatalysis-based air purifiers' efficiency depends on a variety of factors :
Manufacturers most often use titanium dioxide (TiO 2 ) as a catalyst. It is known to be effective against VOCs, gas, odors, mold, fungus, bacteria, and viruses. According to the International Agency for Research on Cancer, titanium dioxide is also a carcinogen. Results from animal studies (ARC, 2006 & Yamashita et al, 2011) indicate that titanium dioxide causes lung cancer and impedes fetal development.
Above all, degradation mechanisms involve dangerous by-products. It is difficult to guarantee that the photocatalytic reaction will be complete, as indicated in the picture. The factors listed can lead to a partial reaction and the emission of toxic by-products. Among them, are ketones and aldehydes have irritant and toxic properties.
For more information, click here and read an excellent French article by Corinne Mandin and Séverine Kirschner.
Natural environments are rich in negative ions. This is precisely the principle on which the air ionizer is based on. However, do you know how this technology manages to capture the pollution particles contained in the indoor air to purify your home?
In December 2019, a respiratory virus of the Coronavirus family appeared in the Wuhan region of China and has now spread to all continents.
Purifying indoor air while protecting your health and the planet is possible! Say goodbye to filters and make way for negative ions: choose an eco-responsible air purifier that will easily reduce energy and resource consumption.