Investigation of cyanide ions adsorbed on platinum and palladium coated silver island films by surface-enhanced Raman spectroscopy

摘要

Bimetallic films prepared by vacuum-depositing platinum onto silver island films have been evaluated for surface-enhanced Raman scattering (SERS), using CN~- as the adsorbate. For platinum overlayers with mean thickness corresponding to 1-2 monolayers the spectrum is dominated by a band consistent with either CN~- adsorbed at the platinum surface or with Pt(CN)_4~-. For thinner platinum overlayers, changes in the spectra due to migration of CN~- from Ag(CN)_2~- to the surface platinum atoms were observed during the first few minutes of laser illumination. Similar palladium-on-silver films showed a prominent SERS band assigned to surface Pd(CN)_4~(2-).