Photocatalytical degradation of selected volatile organic compounds in emission test chambers
(2014)
This work focuses on the photocatalytical degradation of selected volatile organic compounds (toluene, butyl acetate, phenol and limonene) under UV-light and blue LED-light (λ = 444 nm) at different relative humidities. Ceramic tiles coated with titanium dioxide were used as photocatalytical active material. The experiments were performed in 20 l emission test chambers with two different kinds of pollutant supply. Toluene was the compound with the highest degradation rate in all performed experiments. A degradation rate of 24 % was obtained under blue LED-light and a relative humidity of (50 ± 5)% and a degradation rate up to 80 % was obtained under UV-light in dry air.
Since Central Europeans spend most of their time indoors, the quality of the indoor air is important. Sources of volatile organic compounds (VOC) indoors are e. g. building materials, wall and floor coverings and interior equipment, whose emissions might influence the health and wellbeing of people. Photocatalysis is one opportunity to improve the indoor air quality by degrading VOCs ideally to carbon dioxide and water. Titanium dioxide (Ti02) in its anatase modification (band gap of 3.2 eV) is a common used UV-active photocatalytic coating. Because of the lack of UV light indoors Ti02 needs to be modified to be active under visible light too. This work focuses on the photocatalytic degradation of toluene, butyl acetate and limonene under UV LED light and blue LED light in emission test chambers under controlled climatic conditions. These compounds were selected due to their frequent occurrence in the indoor environment and their supply was done with a gas mixing System. Ceramic tiles coated with modified and pure Ti02 were used as photocatalytic active material. Previous results and experimental details were already published by Mull and Wilke (2014).