Photocatalytic degradation of atmospheric fine particulate matter (PM_2.5) collected on TiO₂ supporting quartz fibre filter

Carbonaceous constituents in fine particulate matter (PM_2.5) are often associated with adverse health effects in humans. Although air filtration technology is widely used for preventing exposure to PM_2.5, the trapped PM_2.5 still has hazardous property if not treated subsequently. Thus, this study aimed to realise detoxification of PM_2.5 with a photocatalytic decomposition of carbonaceous compounds in PM_2.5 samples collected on a quartz fibre filter coated with titanium dioxide (TiO₂). The mass of PM_2.5 gradually decreased with time during the UV irradiation with a significant release of carbon dioxide (CO₂) as a product. The analysis of organic carbon (OC) and elemental carbon (EC) using a thermal/optical carbon analyser following the IMPROVE protocol showed that carbonaceous constituents such as OC1, OC2, OC3, OC4, and EC1 fractions were successfully decomposed by UV-irradiated TiO₂, whereas EC2 and EC4 fractions were inert to the photocatalysis. However, a majority of the carbon content, approximately 92% of the total carbon, was reduced by the proposed method. This shows that the photon-induced TiO₂ potentially reduces the hazardous effects of PM_2.5.