Raman spectroscopy of the emersed Ag | alcohol electrochemical interface

Abstract

Raman spectroscopy is used to characterize the molecular structure and orientation of the solvent in electrochemical interfaces at Ag electrodes emersed from methanol and 1-propanol electrolyte solutions. The vibrational behavior of the solvent in the emersed interfaces is compared with that existing in situ as probed by surface enhanced Raman scattering as a function of electrode potential. Changes in peak frequency shifts and relative intensities as a function of potential are maintained upon emersion of the electrode from the alcohol electrolyte solution. These observations suggest that both solvent orientation and bonding environment at the Ag surface remain unperturbed by the emersion process. Additionally, the solvent behavior upon emersion is compared at rough and smooth Ag surfaces. The similarity in the spectra from these two types of surfaces as a function of potential suggests that surface enhanced Raman scattering can provide information about the average interfacial solvent molecules in electrochemical systems.