They are designed only to remove particulate pollutants from the air, so they are not effective at all for removing gaseous pollutants. Ionizers can produce ozone as a side effect, and ozone can have an effect on gaseous pollutants (and not necessarily a beneficial one).

Do ionizing air purifiers really work?

Are they effective? The short answer is yes — however, an air purifier likely won't remove or neutralize all aggravating particles in your home. This is due to the fact that many particles can sit on soft surfaces, such as furniture, bedding, and carpeting, as well as hard surfaces, such as your walls.

Do air ionizers work for Covid?

Portable air cleaners and HVAC filters can reduce indoor air pollutants, including viruses, that are airborne. By themselves, portable air cleaners and HVAC filters are not enough to protect people from the virus that causes COVID-19.