TUTCRIS - Tampereen teknillinen yliopisto

TUTCRIS

Increased propensity of Iaq - for the water surface in non-neutral solutions: Implications for the interfacial behavior of H 3Oaq + and OHaq -

Tutkimustuotosvertaisarvioitu

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut972-976
Sivumäärä5
JulkaisuJournal of Physical Chemistry Letters
Vuosikerta2
Numero9
DOI - pysyväislinkit
TilaJulkaistu - 5 toukokuuta 2011
OKM-julkaisutyyppiA1 Alkuperäisartikkeli

Tiivistelmä

By a combination of surface-sensitive photoelectron spectroscopy and molecular dynamics simulations, we characterize the surface propensity of the iodide anion in aqueous solutions at acidic, neutral, and basic conditions (pH = 1, 6.8 and 13). In both experiments and simulations, an increased surface concentration of I- is found in non-neutral solutions. We interpret these findings in terms of I- surface coadsorption with hydronium at low pH and salting out of iodide by hydroxide from the bulk solution to the surface at high pH. The present study is thus in accord with the picture of a weak surface adsorption of hydronium and surface depletion of hydroxide, being in sharp contradiction with the interpretation of electrophoretic and titration measurements in terms of strong surface enrichment of OH-.

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