SERS and Fourier transform SERS studies of the hexacyanoferrate(III)‐hexacyanoferrate(II) couple on gold electrode surfaces

Surface‐enhanced Raman spectroscopy (SERS) and its Fourier transform (FT) variant were used to study the hexacyanoferrate(III)‐hexacyanoferrate(II) couple at the surface of gold electrodes. The effects of potential, Fe(CN) concentration and base electrolyte (KCl) concentration were measured, and point to distortion of the Fe(CN) ion on the surface of the electrode. The Fe(CN) ion was found not to be strongly adsorbed when a base electrolyte concentration of > 10 m M was used, but the strong adsorption of the Fe(CN) ion was demonstrated. The increased resolution that is possible when using the FT‐SERS technique allows for the partial resolution of bands in the CN stretching region, and thus the construction of a model for the hexacyanoferrate(III) system.