Structure of Silver (100) and (111) Single‐Crystal Surfaces Obtained by Chemical Polishing

Abstract

Interest has been increasing in the investigation of electrochemical reactions on single-crystal electrode surfaces. Electrode processes having a pronounced dependence on the particular single-crystal surface include hydrogen adsorption, underpotential deposition of metals, oxidation of organic molecules, and oxygen reduction. Inadequately characterized single-crystal surfaces, however, may lead to misleading results. Atomically flat, well-ordered surfaces are needed in order to obtain meaningful data. Ultrahigh vacuum techniques such as low energy electron diffraction (LEED), Auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS) can facilitate the characterization of such surfaces and verification of freedom from adsorbed impurities, but these techniques are ex situ. Elaborate systems have been developed for preparing and characterizing single-crystal electrode surfaces in ultrahigh vacuum and then transferring them into the electrochemical environment and vice versa under conditions designed to minimize structural changes and contamination. Experiments with these transfer techniques, however, are very time consuming and impose substantial restraints on the types of electrochemical systems that can be studied because of factors such as the use of completely volatilizable electrolytic solutions and thin-layer cell configurations.