In situ Raman spectroscopy studies of the interface between silver(111) electrodes and alkaline NaF electrolytes

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 −0.6 V vs. Hg|HgO electrode at pH 11. Two potential-dependent Raman bands ν 1 at 540 to 560 cm −1 and ν 2 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 D 2 O solutions, ν 2 being shifted to values of 550 to 570 cm −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.

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