| AVS 54th International Symposium | |
| Surface Science | Thursday Sessions |
| Session SS1-ThA |
| Session: | Environmental Surfaces |
| Presenter: | J.C. Hemminger, University of California, Irvine |
| Authors: | M.A. Brown, University of California, Irvine J.T. Newberg, University of California, Irvine M.J. Krisch, University of California, Irvine B.S. Mun, Advanced Light Source, LBNL P. Ashby, Molecular Foundry, LBNL J.C. Hemminger, University of California, Irvine |
| Correspondent: | Click to Email |
Ozone, a powerful oxidant trace gas found throughout both the troposphere and stratosphere is believed to oxidize alkali halides in the form of sea-salt aerosols and is considered to be a significant candidate for the formation of reactive gas phase molecular halogens. Recent studies suggest that although iodide is a minor component of sea-salt spray its concentration at the interface of aqueous solutions and at the interface of dried solid crystalline sea-salt particles is greatly enhanced relative to the bulk concentration. X-ray photoelectron studies described here show, under conditions in which a low defect density KI surface is completely devoid of adsorbed water molecules the surface oxidation by ozone results in a thin molecular layer of KIO3 that is self-passivating. We report for the first time the reaction probability (?) at room temperature for the reaction KI(s) + O3(g) ? KIO3(s) of ? = 1.4 (±0.7) x 10-4. Results of the low defect density system are compared with the results of a high defect density polycrystalline KI surface. In-situ SPFM imaging provides molecular insight into the site specificity of the chemical reaction on the surface of KI (100).