BEHAVIOR OF THE 1025 CM(-1) BAND OF SERS SPECTRA DUE TO PYRIDINE ON A SILVER ELECTRODE IN AQUEOUS HALIDE MEDIA

The 1025 cm-1 band which occurs in the SERS of pyridine and halide anion was investigated in detail on a silver electrode in neutral and acidic solution. The 1025 cm-1 band was observed to increase in intensity when the silver electrode was treated with the ORC procedure in the presence of pyridine and halide and the concentration of pyridine was then diluted in neutral solution. On the other hand a band began to appear strongly at 1025 cm-1 when the solution was acidified with HCl after the ORC. It was confirmed that the 1025 cm-1 band appearing on dilution in neutral solution has by the same origin as the 1025 cm-1 band which appeared on acidification. The behaviour of the band can be understood if it is assumed that the species giving rise to the 1025 cm-1 band is a silver-pyridine-halide complex generated by the electrode reaction during the ORC.