On the Seventieth Birthday of J. Japaridze

Russian Journal of Electrochemistry -     

Electrical Double Layer at a Liquid Pb–Ga Electrode in Propylene Carbonate Solutions

Differential-capacitance curves and potentials of zero charge are obtained for a liquid Pb–Ga electrode in propylene carbonate (PC) solutions of surface-inactive electrolyte LiBF₄and 0.1 M solutions of LiBr and LiI. In PC and water, double-layer parameters of Pb–Ga differ from those of Ga. The lyophilicity of Pb–Ga in respect to PC is lower than that of Ga and coincides with that of Hg.     

Structure of Electrical Double Layer on Liquid Pb–Ga Alloy in Aqueous Electrolytes

A new electrode, which is a liquid Pb–Ga alloy (0.06 at. % Pb), is developed and studied. It is shown that the alloy's double-layer characteristics dramatically differ from characteristics of a Ga electrode and are practically identical to characteristics of a Pb electrode. Hence, the Pb–Ga electrode in fact models electrochemical properties of a liquid Pb electrode. It is established that the metallic capacitance of the Pb–Ga electrode occupies an intermediate position between values of metallic capacitance of Ga and Hg electrodes, provided the metal–water chemisorption interaction is absent and the electrode charge is fixed. Hydrophilicity of the Pb–Ga electrode is substantially lower than hydrophilicity of a Ga electrode and coincides with hydrophilicity of an Hg electrode. It is shown that In–Ga, Cd–Ga, and Pb–Ga electrodes have close values of the electrochemical work function, and the chemisorption potential drop of the solvent in them increases in the series Pb–Ga < In–Ga < Cd–Ga with decreasing distance of closest approach of water molecules to the ionic core of the metal. The absorbability of anions at the Pb–Ga electrode increases in the series BF^– ₄= SO^2– ₄< Cl^–< Br^–< I^–.     

Electrical Double Layer Structure in Surface-Inactive Electrolytes on a Liquid Cd–Ga Electrode in Methanol and Propylene Carbonate

Differential capacitance curves and potentials of zero charge are obtained for liquid Cd–Ga electrodes in methanol and propylene carbonate solutions of a surface-inactive electrolyte. It is found that double-layer characteristics of the Cd–Ga electrode differ from those of a Ga electrode both in nonaqueous solutions and in water. The lyophilic nature of the Cd–Ga electrode, relative to methanol and propylene carbonate, is shown to approach that of the In–Ga electrode. In the absence of a metal–solvent chemisorption interaction, the difference between reciprocal metallic capacitances for Cd–Ga and Hg electrodes is independent of the solvent nature. The chemisorption interaction between the solvents and Cd–Ga, Ga, and In–Ga electrodes increases with the solvents' donor number.     

The influence of crystallographic inhomogeneity of a polycrystalline electrode surface on the behavior of the electric double-layer

The specific features of the electric double-layer structure at polycrystalline electrodes in the absence of specific ion adsorption have been examined for two different models: Model I and Model II. In the case of Model I each of the faces showing on the surface of a polycrystalline electrode retains its own Helmholtz and diffuse double layers. In the case of Model II the faces retain only their own Helmholtz layer, whereas the diffuse layer is common to the entire electrode surface. The difference of zero charge potentials of the faces is defined both by their dissimilar hydrophilic properties and by different work functions. The experimental data available at present on the electric double-layer structure at polycrystalline electrodes for which the potentials of zero charge of the faces differ significantly are described by Model I.     

The 2005 Frumkin Award competition for young scientists

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The 2005 Frumkin Award competition for young scientists