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O: Fachverband Oberflächenphysik

O 18: Solid-Liquid Interfaces I: Structure and Spectroscopy

O 18.7: Vortrag

Montag, 18. März 2024, 16:30–16:45, H 1012

Self-organized structures of carboxylic acids on the Au (111) electrode surface — •Kristin Gratzfeld¹, Anna J. Kny¹, Tomasz Kosmala², Radosław Wasielewski², Marek Nowicki², Klaus Wandelt¹, and Moritz Sokolowski¹ — ¹Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Germany — ²Institute of Experimental Physics, University of Wrocław, Poland

We investigated the self-ordered structures of 3,4,9,10-perylene-tetracarboxylic acid (PTCA) and 1,4,5,8-naphthalene-tetracarboxylic acid (NTCA) on the Au(111) electrode interface in an aqueous electrolyte. Electrochemical studies of PTCA were perfomed before [1], however no structural data was reported, yet. We used cyclic voltammetry (CV) with in situ electrochemical STM (EC-STM): By tuning the electrode potential, we can observe different ordered phases of both molecules on the Au(111) electrode surface. We will discuss the geometrical differences of the ordered phases and why we observe the transitions between phases at different electrode potentials on the Au(111) surface. When shifting to more positive electrode potentials, we observe that the PTCA molecules in the ordered phases change from an upright to a tilted and finally to a flat orientation. In contrast, for NTCA we observe only ordered phases of tilted molecules.

This work was supported by the DFG through the research training group 2591, the DAAD (Deutscher Akademischer Austauschdienst)program Ostpartnerschaften and the NAWA (National Agency for Academic Exchange) program.

[1] Journal of American Society, 138, 1490 -1493, 2016.

Keywords: Au(111) surface; electrochemical scanning tunneling microscopy; cyclic voltammetry (CV); surface structure