Surface-enhanced Raman spectroscopy of pyridine adsorbed on rhodium modified silver electrodes

Abstract

Surface-enhanced Raman scattering (SERS) has been observed from pyridine adsorbed on a silver electrode modified by electrodeposited rhodium films. Intense vibrational modes, attributed to pyridine adsorbed at rhodium sites, are detected at 1020, 1046 and 646 cm −1, clearly distinct from the 1010, 1036 and 625 cm −1 bands due to pyridine adsorbed on unmodified silver. These bands slowly decrease in intensity with increasing thickness of the rhodium film, but are still visible at deposition of up to 20 or more equivalent monolayers of rhodium. The extent of bonding between pyridine and the rhodium sites is potential dependent.