Regensburg 2019 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 33: Solid-Liquid Interfaces III
O 33.3: Vortrag
Dienstag, 2. April 2019, 14:30–14:45, H10
Trapped electrons and their impact on oxygen reactivity near DMSO/Cu(111) interfaces — •Angelika Demling1, Sarah B. King2, Katharina Broch3, and Julia Stähler1 — 1Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany — 2Department of Chemistry and James Franck Institute, University of Chicago, 929 E 57th Street, Chicago, IL 60637, USA — 3Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
DMSO is a common non-aqueous solvent with the potential to be used in lithium-oxygen batteries due to its ability to catalyze superoxide formation [1]. In this study we investigate the electron dynamics in DMSO films on Cu(111) using time- and angle-resolved two-photon photoemission and disentangle the individual steps of charge transfer prior to superoxide formation: Electrons are injected from the metal to the DMSO where they form small polarons on sub-picosecond time scales. The subsequent trapping extends the electronic lifetimes to several seconds [2]. Electron attachment to co-adsorbed O2 reduces these lifetimes significantly and leads to negative surface charging.
These results highlight the complexity of a standard electrochemical process like superoxide formation.
[1] K. M. Abraham, J. Electrochem. Soc. 162, A3021 (2015)
[2] S. B. King et al., J. Chem. Phys. 150, 041702 (2019)