Journal of Electroanalytical Chemistry, Vol.505, No.1-2, 95-99, 2001
Surface Raman spectroscopic studies on the adsorption of pyridine at bare iron electrodes
Surface-enhanced Raman spectroscopic (SERS) studies have been extended successfully to iron electrodes by using a highly sensitive confocal microprobe Raman system. Several surface roughening procedures were attempted to obtain high-quality surface Raman spectra of pyridine on iron electrodes. Results show that proper surface roughness factor can not only increase the surface area, but also induce a weak SERS effect. Potential-dependent surface Raman spectra of pyridine in neutral solution suggest that the pyridine molecule may be adsorbed onto the iron electrode through the nitrogen atom by a coordination bond of Fe-N in an end-on configuration (or slightly tilting). Decreasing the solution pH value to ca. 2.0 did not affect the adsorption of pyridine and the pyridinium ion may dissociate before its adsorption onto the iron surface.