|approved||cobet_abstract_extended.pdf||2015-04-28 05:20:19||Christoph Cobet|
Author: Christoph Cobet
Requested Type: Pre-Selected Invited
Submitted: 2015-03-16 05:37:45
Co-authors: Gh. Barati, V. Solokha, K. Hingerl
Johannes Kepler University
Electrochemical reactions on metal electrodes are subject of scientific studies since many years and Cu is probably the most investigated material. The interest is motivated e.g. by questions concerning corrosion, electro-polishing, or catalytic reactions. It is evident that a rigorous understanding should include also a microscopic description of the surfaces as it is known already for surfaces in UHV. But unfortunately, many classical surface sensitive techniques cannot be applied in liquid environments. A rather promising approach seems to be the application of optical methods and in particular polarization optical methods with a distinct surface sensitivity combined with electrochemical scanning tunneling microscopy and classical cyclic voltammetry. With this combination we obtained a monitoring tool where the local appearance on the atomic scale and the dynamics of interface transformations/reactions can be interrelated. An example is the Cu(110) surface in HCl solution. With Cl adsorption the surface energy minimizes by a formation of monoatomic steps parallel to the  direction which finally ends in a faceting of the surface. It turns out that characteristic redox peaks in the Faraday current correlate in parts with the stabilization of certain surface morphologies while other leave the surface unchanged and relate more to dissolution processes.