Migration Effects in Reversible System [Fe(CN)6]3–/4– on a Microelectrode

Migration factors Y are determined for an [Fe(CN)₆]^3–/4– reversible system at a platinum microelectrode 10 m in radius by measuring anodic and cathodic limiting currents at different concentrations of the redox forms in solution, from which Y _a and Y _c are calculated. The obtained results agree with theory. The experimental error for the Y _a/Y _c ratio is smaller than for each factor taken separately.     

Analysis of discrete spectra of electrochemical noise of lithium power sources

Journal of Solid State Electrochemistry - The Fourier, Daubechies, and Chebyshev transforms are used to analyze discrete spectra of electrochemical noise of lithium power sources under the...     

Electrochemical impedance of microelectrodes

The influence of the radius (10 <a < 1500 μm) of a Pt disk electrode on the impedance frequency spectrum of the [Fe(CN)₆]^3-/4- reversible system is studied in the frequency range 5 × 10^-3 to 10³ Hz. The impedance is calculated by applying the Fourier transform to potential and current pulses of various lengths obtained when imposing a step potential. For electrodes witha < 100 μm, the spectrum in the complex plane has the form characteristic of microelectrodes, while for electrodes of higher radii, it corresponds to a finite Warburg impedance. The main impedance parameters, such as the charge transfer resistance, the diffusion resistance, and the frequency in the maximum of the imaginary constituent are determined. The latter decreases with an increase ina by the lawf* ∼ 1/a² at lowa and is independent ofa on electrodes witha > 100 μm, which agrees with the impedance theory for microelectrodes     

Diffusion Conductivity of Electrode Processes under Conditions of Natural Convection

The diffusion conduction = di/d (where i is the current and is the overvoltage) in reversible system [Fe(CN)₆]^3–/4– is measured by the electrochemical impedance method under isothermal and nonisothermal conditions of natural convection. Platinum disk electrodes 3 mm and 20 m in diameter are used. For a macroelectrode under isothermal conditions, passes through a maximum near equilibrium and tends to zero at 0. Under nonisothermal conditions and for a microelectrode under isothermal conditions, achieves a maximum near equilibrium. These data correlate with the dependence of the diffusion layer thickness and quantitatively agree with theory.     

The effect of papaverine on cadmium electrodeposition on glassy carbon electrode modified with mercury

The effect of papaverine on cadmium electrodeposition is studied. It is shown that cadmium forms an anionic complex with papaverine in the chloride solutions.     

Electrochemical Memory Cells*

Principles of writing and reading the data in a binary code in memory cells based on electrochemical cells are considered. The realization of a multibit cell with a liquid electrolyte, where the data are written by a successive cathodic deposition of alternating metallic layers with different electrochemical properties and thicknesses on the working electrode, is shown. The layer deposition can be controlled by current or voltage pulses of different amplitudes and lengths. The written data are read on the basis of a successive controlled anodic dissolution of the multilayer structures. Attainable parameters of the electrochemical memory of an integral design combining a multicell memory and a controller on the same crystal are estimated.     

Identification of alkaloids using the stripping voltammetry method

The possibility in principle is shown of using the stripping voltammetry method for identification of alkaloids with the help of a test system in the form of an electrolyte solution containing a set of cations of different metals.     

Diffusion Impedance of Electrodes of Different Size in Isothermal and Nonisothermal Natural Convection Conditions

The impedance for a reversible K₃[Fe(CN)₆]/K₄[Fe(CN)₆] system is measured at vertical platinum disk electrodes of different diameter in isothermic natural convection conditions and during nonisothermal heating of the electrode. The frequency dependence of the diffusion impedance is described by a classic formula for a finite Warburg impedance. The dimensionless frequency ²/D in the extreme point of the impedance spectrum approached 2.5, in accordance with the theory. Under isothermic conditions near equilibrium, for large-diameter (d > 1 mm) electrodes, the characteristic frequency that corresponds to the extreme point, *, is proportional to the square root of the redox-component concentration, overvoltage, and d ^–1/2. In nonisothermal systems, this frequency is proportional to the square root of the temperature gradient at the electrode/solution interface. These regularities agree with the theory of natural convection. For microelectrodes, the impedance frequency spectrum conforms to the Fleischmann–Pons theory and * is proportional to d ^–2.