Electrode surface activation for SERS

Typical cyclic voltammograms for a silver electrode in 0.1 M KC1 and in 0.1 M K2S04 supporting electrolytes are shown in Fig. 10. These are produced under ORC conditions typically used for SERS activation. During the oxidation half-cycle, the Ag° electrode surface is oxidized to Ag+, which forms an insoluble layer of AgCl or Ag2S04 on the surface. The amount of 

An illustration of the effect of successive ORC treatments of a silver electrode on the SERS of adsorbed species [6] is shown in Fig. 11. The progressive increase in Raman band intensities for the co-adsorbed N03 and EDFA species through five separate ORCs is clearly seen. 

A small number of ORCs is usually sufficient to achieve the maximum enhancement factors for silver electrodes. Indeed, repeated cycling beyond four or five times has been observed to have a detrimental effect on the SERS enhancement. A rather different situation is found for gold, however. It has 

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