CHAPTER 7: Photocatalytic Purification and Disinfection of Air

This chapter considers aspects of gas-phase photocatalysis related to indoor or close space air purification. The formation of diverse by-products during photocatalytic oxidation of air pollutants is very important. However, advanced photocatalysts and low concentrations are leading to clean oxidation with inorganic compounds as the only products. The influence of temperature, air relative humidity, pollutants concentration, and irradiance on the oxidation processes is considered in detail. Microbiological airborne objects and even pollen can be inactivated and mineralized with the help of TiO₂-based photocatalysts. Research and commercial prototype air purification reactors are considered in this chapter. Finally, combined processes utilizing additional catalysts and oxidants are demonstrated to be of great promise for practical air purification. While much intensive research has been carried out in the field during the last 20 years, there are still questions and underdeveloped aspects in order for photocatalysis to become competitive widespread air purification technology.