Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 20: Solid / liquid interfaces II
O 20.1: Vortrag
Montag, 14. März 2011, 17:15–17:30, WIL B321
dynamic electromechanical response during cyclic voltammetry: measurement strategies — •Qibo Deng1,2, Maxim Smetanin1,2, and Jörg Weißmüller1,3 — 1Institute of Materials Physics, Hamburg University of Technology, Hamburg, Germany — 2Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany — 3Institute of Materials Mechanics, Helmholtz Zentrum Geesthacht, Geesthacht, Germany
We explore experimental strategies for measuring the impact of elastic strain on the electrode potential, E, of Au in weakly adsorbing aqueous electrolytes. More precisely, our experiment aims at measuring the potential-strain response dE/de|q at different states of the electrode. The symbols q and e denote superficial charge density and tangential (elastic) strain, respectively. Emphasis is on measuring the variation of response with E during cyclic voltammetry in extended potential intervals, including dominantly capacitive regions of the voltammogram as well as electrosorption processes. By means of validation, we explore three independent strategies for separating the cyclic variation of potential of current from the voltammogram proper. The results are in close quantitative agreement. We describe the setup and report results for 111-textured gold electrodes in aqueous H2SO4 and HClO4. We find that the response is generally negative-valued. Furthermore, the magnitude of response peaks at a potential which is close to the pzc and which is displaced relative to the potential of largest AC-capacitance.