Surface Raman spectroscopic studies of pyrazine adsorbed onto nickel electrodes

Surface enhanced Raman scattering from pyrazine adsorbed on roughened Ni electrodes was observed for the first time. A special surface roughening procedure was carried out by a HNO3-etching method to obtain high-quality surface spectra. The significant differences derived from the comparison of the spectra at different electrodes suggest stronger interactions of pyrazine with Ni than with the typical SERS active metals of Ag, Au and Cu. Some forbidden vibrational bands of pyrazine were detected due to the lowering of the symmetry from D-2h to C-2v by the strong adsorption on the surface.