OPTICAL STUDIES ON THE QUENCHING OF THE SEARS ACTIVITY OF SILVER ELECTRODES

The reflectivity of a polycrystalline silver electrode in aqueous 0.1 M KCl, 50 mM pyridine electrolyte solution after the activation for surface enhanced Raman scattering (SERS) by an oxidation-reduction cycle shows no electromagnetic resonances within "pores", in agreement with the relatively low roughness factor. Cathodic pulses quench the SERS intensity, which recovers within 30 min. The changes of the reflectivity during quenching and recovery are small, excluding important changes of the classical electromagnetic enhancement. We discuss the results within the models of "SERS-active sites" and "trapping" of pyridine and Cl- in grain boundaries. © 1990.