Average air purifiers are equipped with “physical” filters like HEPA or active carbon filters, that take this name because they physically block pollutants, collecting them on the filter meanwhile the air pass through the air purifier.
The result will be a filtered air from pollutants but an increasingly saturated filter with pollutants (powders, PM, bacteria etc.), that for this reason after a given period of time must to be thrown away and replaced with a new filter in order to start the collecting process from the beginning. (download the scientific publication on microbial growth on activated carbon filters)
Of course, if you don’t change the filter, it will be more and more saturated with pollutants and at one point, some collected pollutant could be released, because the already saturated filter can’t block anymore.
PHOTOCATALYSIS instead work with a totally different principle.
Instead of blocking the particles, it chemically “attacks” them breaking their bonds and degrading them. So, if I have a pollutant molecule, it will be shattered. The degrading process continues until only CO2 and H2O remain, that are not dangerous substances. The same principle works for virus and bacteria, their wall are damaged until they die.
How Photocatalysis works?
The patented substance on the filter is photo-active, it is indeed “activated” by light, when it is hit by the light, it generates free radicals (molecules that are neutral, but charged and very reactive), that attack pollutant molecules (as bacteria and viruses) that are moving nearby the filter or that are deposited on it, breaking their chemical bonds and degrading them.
For this reason the pollutants are not collected on the filter but they are transformed in not dangerous substances, this is why you don’t have to periodically change the filter.
Free radicals produced by the process are not dangerous for humans, because they can survive for no more of some micron, because there’s no risk that they get in contact with people. Photocatalysis indeed take place only locally, on the filter or in close proximity.
Another advantage of our process is the use of visible light instead of UV light, that is more dangerous and produce ozone (dangerous too). In the market are present products with photocatalysis activated by UV light.
- HEPA and active carbons filters collect pollutants, until filter saturation, with the risk, if it is not frequently changed, of a not efficient filtration and even accumulated pollutants release. You have to consider also the great cost of filter changes during the year.
- Our filters based on photocatalysis don’t collect pollutants but they shoot down them, this is why there is no risk of a saturated filter and there’s no need of filter replacements.
- Broad Spectrum Microbicidal Activity of Photocatalysis by TiO2
- Photocatalytic disinfection using titanium dioxide: spectrum and mechanism of antimicrobial activity
- The inactivation effect of photocatalytic titanium apatite filter on SARS virus
- Microbiological disinfection of water and air by photocatalysis
- Inactivation and mineralization of aerosol deposited model pathogenic microorganisms over TiO2 and Pt/TiO2
- Photocatalytic inactivation of influenza virus by titanium dioxide thin film