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Abstract:
The electrochemical interface between Ag(111) single crystal and NaF + NaOH electrolytes at various pH values has been studied
using cyclic voltammetry and in situ Raman spectroscopy. Submonolayer oxidation starts well below bulk silver oxide formation at
potential about -0.6V vs. HglHgO electrode at pH 11. Two potential-dependent Raman bands v1 at 540 to 560cm-1 and v2 at 803 to
819 cm-1 in basic NaF electrolytes are attributed to Ag-OH stretching and AgO-H bending vibrations of electrochemisorbed hydroxide
species. Strong isotope effect is observed in D20 solutions, v2 being shifted to values of 550 to 570cm-1. Fluoride stabilizes the adsorption of hydroxide species. A multistep scheme is proposed that describes the mechanism of formation of hydroxide/oxide species at the considered silver-electrode surface.