| Title: | "A chamber study on the reactions of O3, NO, NO2 and selected VOCs with a photocatalytically active cementitious coating material" |
| Author(s): | Mothes F; Boge O; Herrmann H; |
| Address: | "Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstrasse 15, 04318, Leipzig, Germany. Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstrasse 15, 04318, Leipzig, Germany. herrmann@tropos.de" |
| Journal Title: | Environ Sci Pollut Res Int |
| DOI: | 10.1007/s11356-016-6612-6 |
| ISSN/ISBN: | 1614-7499 (Electronic) 0944-1344 (Linking) |
| Abstract: | "Chamber studies were performed to investigate the efficiency of a photocatalytically active cementitious coating material to depollute contaminated air. The results showed a photocatalytic effect on ozone (O3), proven by an increase of the geometric uptake coefficient from 5.2 x 10(-6) for the inactive to 7.7 x 10(-6) for the active material under irradiation. Measured first-order rate constants for nitrogen oxides (NOx) under irradiation are in the range of 2.6-5.9 x 10(-4) s(-1), which is significantly higher compared to the inactive material (7.3-9.7 x 10(-5) s(-1)) demonstrating the photocatalytic effect. However, no significant photocatalytic degradation was observed for the studied volatile organic compounds (VOCs) toluene and isoprene resulting in only an upper limit uptake coefficient of 5.0 x 10(-7) for both VOCs. In all experiments using the photocatalytically active material, a clear formation of small carbonyl (C1-C5) gas phase compounds was identified which is suggested to result from the photocatalytic degradation of organic additives. In contrast to the uptake observed for pure O3, during the experiments with NOx (>/=50 % relative humidity), a clear photocatalytic formation of O3 was observed. For the material investigated, an empirically derived overall zero-order rate constant of k 0 (O3) approximately 5 x 10(7) molecules cm(-3) s(-1) was determined. The results demonstrate the necessity of detailed studies of heterogeneous reactions on such surfaces under more complex simulated atmospheric conditions as enabled by simulation chambers" |
| Keywords: | Air Pollutants/*chemistry Air Pollution/*prevention & control Nitrogen Oxides/*chemistry Ozone/*chemistry *Photolysis Volatile Organic Compounds/*chemistry Air pollution Cementitious material Heterogeneous photocatalysis NOx Titanium dioxide Voc; |
| Notes: | "MedlineMothes, F Boge, O Herrmann, H eng Germany 2016/04/23 Environ Sci Pollut Res Int. 2016 Aug; 23(15):15250-61. doi: 10.1007/s11356-016-6612-6. Epub 2016 Apr 22" |
