Photocatalytic Air Purification

Titanium dioxide represents an effective photocatalyst for destruction of volatile organic compounds (VOC), NOx and SO2 in indoor and outdoor air. The mechanism of selected pollutants removal as well as the dependence of reaction rate on some key influencing factors are discussed. Recent papers and patents considering photocatalysts preparation and immobilization techniques including type of supports, surface pretreatment procedure are reviewed. Photocatalytic reactors are designed in order to provide strictly controlled conditions for photocatalytic air purification. Some reactors can be utilized in commercial applications as a part of HVAC systems (Heating, Ventilation and Air Conditioning) but most of them are used in laboratories to measure the activity of different types of photocatalysts applied for gas streams treatment. Examples of photoreactors used for gas phase treatment are presented.