Adsorption of iodide ions at the Bi(111) | propylene carbonate plus dimethyl carbonate interface

The adsorption of I- anions on the Bi(1 1 1) single crystal plane from mixed solutions of propylene carbonate and dimethyl carbonate (1:1) has been investigated with impedance measurements. Both electrode charge and electrode potential were applied as the independent electrical variables in the calculations of the ionic charge due to the specific adsorption following the mixed-electrolyte method. The Gibbs energy of I- anions adsorption has been calculated using the virial adsorption isotherm. It was found that under comparable con-ditions, the standard Gibbs energy values obtained at constant electrode potential and at constant electrode charge, are coincident and the Gibbs energy of I- anion adsorption in the mixture is only slightly lower than in the pure propylene carbonate or ethylene carbonate solutions. However, at higher concentrations of iodide ions, the specific adsorption charge values in the mixture are remarkably lower than in pure propylene carbon-ate caused by different lateral repulsion values of iodide ions on the electrode surface in different systems. The electrosorption valency values have been calculated and it was found that this parameter is higher in the mix-ture than in pure propylene carbonate or in other organic carbonate solvents.

Automated summary

The adsorption of I- anions on the Bi(1 1 1) single crystal plane from mixed solutions of propylene carbonate and dimethyl carbonate has been investigated. The Gibbs energy of I- anions adsorption has been calculated using the virial adsorption isotherm. The results show that the adsorption of I- anions in the mixture is slightly lower than in the pure propylene carbonate or ethylene carbonate solutions.