Time dependence of surface enhanced Raman scattering during and after oxidation-reduction cycles

The time development of surface enhanced Raman scattering from silver electrodes immersed in chloride and thiocyanate electrolytes has been measured during and after oxidation-reduction cycles of the linear scan and double step type. Raman spectra were recorded in times as short as 0.1 s, using a spectrograph equipped with an optical multichannel detector and analyzer. Correlations were found between Raman spectra and the current-potential-time curves. In mixed electrolytes the displacement of one anion by a more strongly adsorbing anion was observed. In addition, unexpectedly large effects of laser irradiation and hydrogen evolution prior to the oxidation-reduction cycle have been observed in the intensity of SERS bands after the cycle. These last two effects are attributed to the formation of peculiar surface morphologies. © 1983 Elsevier Sequoia S.A.