Abstract
The properties of a halogen-covered platinum(111) surface have been studied by using density functional theory (DFT), because halides are often present at electrochemical electrode/electrolyte interfaces. We focused in particular on the halogen-induced work function change as a function of the coverage of fluorine, chlorine, bromine and iodine. For electronegative adsorbates, an adsorption-induced increase of the work function is usually expected, yet we find a decrease of the work function for Cl, Br and I, which is most prominent at a coverage of approximately 0.25 ML. This coverage-dependent behavior can be explained by assuming a combination of charge transfer and polarization effects on the adsorbate layer. The results are contrasted to the adsorption of fluorine on calcium, a system in which a decrease in the work function is also observed despite a large charge transfer to the halogen adatom.
Original language | English |
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Pages (from-to) | 152-161 |
Number of pages | 10 |
Journal | Beilstein Journal of Nanotechnology |
Volume | 5 |
Issue number | 1 |
DOIs | |
Publication status | Published - 10 Feb 2014 |
Externally published | Yes |
Keywords
- Density functional theory
- Ionicity
- Polarizability
- Surface dipole
- Workfunction