In non-aqueous solvents, alkali metal or alkaline earth metal ions as supporting electrolytes often cause specific or abnormal phenomena, much different from non-metallic (R₄N⁺) ions as the supporting electrolytes. The possible candidates of the specific phenomena are: (1) the changes in solvation conditions of the metallic cations, (2) the increase in Coulombic interaction between the metal cations and anions with decreasing permittivity, (3) possible adsorption of the metal ion, (4) liquid junction potential hard to be evaluated. However, many abnormal phenomena cannot be interpreted comprehensively based on only these factors. We have set up a hypothesis that the direct chemical interaction between alkali metal or alkaline earth metal and various anions (excluding ClO₄^- etc.), in non-aqueous solvents as well as aqueous solutions containing concentrated salts, could cause the abnormal phenomena. The hypothesis (the coordination ability of alkali metal or alkaline earth metal ions) has been successfully demonstrated not only by means of polarography, conductometry, and various spectroscopic technics, such as UV-visible, NMR, and Raman, but also with the assistance of reaction kinetics and theoretical calculations. Finally, we have succeeded in dissolving pure gold in the mixed solution between dilute nitric acid and the seawater.

In this review article, I focus on some interesting features regarding the electrochemistry and spectroelectrochemistry of biological redox molecules and proteins as well as of nanocarbons, in which the following four topics are described: i) electrochemistry of redox protein in synthetic lipid films, ii) electrochemistry of fullerenes (1)-fullerene C₆₀ lipid film on electrodes, iii) electrochemistry of fullerenes (2)-fullerenes and metallofullerenes embedded in lipid films on electrodes, and iv) electrochemistry of carbon nanotubes-determination of precise redox potentials and their empirical equation as well as carbon nanotube-based fuel cells with high performance.

Three kinds of derivations of the steady-state diffusion-controlled current at an inlaid micro-disk electrode are presented here without using the complex variable theory. The two of them are modifications of equations for capacitors at an ellipsoid, one being a solution of the Laplace equation by use of equi-potential surfaces, the second being a determination of potential in an ellipsoidal shell by the Gauss law. The third is a solution of Laplace equation in the ellipsoidal coordinates.