Effect of the nature of the metal on the dielectric properties of polar liquids at the interface with electrodes. A phenomenological approach

Abstract

The dielectric behaviour of water, DMSO and ACN at the interface with transition and non-transition metals is examined by analysing the inner-layer capacity as a function of the metal surface chemical affinity. An, inner-layer capacity in the absence of metal-solvent specific interaction is defined and derived by graphical correlations. The permittivity of the surface phase of the solvent under these conditions is derived and analysed to elucidate the nature of the factors contributing to the dielectric behaviour at an interface. The capacity-potential curves for Fe, as a typical transition metal, are elaborated to investigate the orientation of the solvent on the surface and the applicability of the Gouy-Chapman-Stern model. Suggestions on the nature of the metal-water surface bond are given on the basis of the derived parameters. The structure of the double layer in ACN at transition metals is discussed in the light of recent measurements.