Electrochemical and surface enhanced Raman scattering studies of bromide ion adsorption at silver electrodes in a series of normal alcohols

Br^- surface coverage as a function of electrode potential is quantitatively determined using the Hurwitz-Parsons analysis of differential capacitance data at Ag electrodes in the series of normal alcohols, methanol through pentanol, containing LiBr. Values for the potential of zero charge (pzc) are estimated from these data. Surface-enhanced Raman spectroscopy (SERS) data in the ν(Ag-Br) region show the presence of a ν(Ag-Br) feature at potentials positive of the pzc which supports strong specific adsorption of Br^- in these media. An excellent correlation between the SERS intensity and the Br^- surface coverage determined from differential capacitance is observed. Bands attributed to hindered translational modes of trace interfacial water are also observed.