Testing the efficacy and the potential effect on indoor air quality of a transparent self-cleaning TiO2-coated glass through the degradation of a fluoranthene layer

Self-cleaning glass can be obtained by coating glass with a transparent, thin layer of TiO2 nanoparticles. To test the self-cleaning properties, fluoranthene-the most abundant polycyclic aromatic hydrocarbon in the atmospheric particulate matter-was sprayed over the glass. Under solar-like UV light, not only was fluoranthene removed at a rate of ca. 0.73 nmol/h per cm(2) of glass but also all fluoranthene degradation products were, and thus the coated-glass transparency was recovered, which did not occur with noncoated glass. The fluoranthene percentage converted to volatile carbonyl products released into ambient air was lower with than without TiO2 coating; i.e., the self-cleaning glass could have a positive influence on indoor air quality. Mechanisms are discussed to account for the main primary products among the 40 fluoranthene photocatalytic degradation intermediate products which we identified.