Surface‐enhanced Raman scattering (SERS) at Copper(I) oxide

Surface-enhanced Raman scattering spectra of pyridine at a copper(I) oxide hydrosol and at Cu2O-covered copper electrode produced by ‘oscillating reaction roughening’ are reported. It is shown that on such surfaces pyridine molecules adsorb as pyridinium cations. The ‘oscillating reaction’ pretreatment yields a passivated Cu surface which does not undergo any reduction during the cathodic scan, producing a SERS spectrum of pyridinium cations even after decreasing the electrode potential to strongly negative values. © 1998 John Wiley & Sons, Ltd.