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Abstract

The adsorption of hydroxide on the Ag(110) surface has been studied with cyclic voltammetry, in situ second harmonic generation (SHG), and ex situ low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED). OH- is found to be adsorbed on the Ag(110) surface at potentials negative of the potential of zero charge, forming small antiphase domains of c(2 x 6) symmetry. Further adsorption leads to longer-range order and the removal of antiphase domain boundaries and is associated with a current peak in the cyclic voltammogram (CV). Concurrently, a change in symmetry patterns is observed in SHG. A c(2 x 2) pattern gradually replaces the c(2 x 6) pattern as the potential, and the OH- coverage, is increased. At the beginning of the second current wave, another symmetry change takes place which is accompanied by a sharp change in the LEED pattern from a c(2 x 2) pattern to a (1 x 1) pattern with strong background, indicating a disordered adlayer. However, RHEED results show that some patches of c(2 x 2) structure remain on the surface. The correlation between SHG and diffraction measurements and comparison of the information obtained from each technique allow us to develop a detailed picture of the structures and electronic effects at the Ag(110) alkaline electrolyte interface.