Potential Sweep Voltammetry Research Articles

Study of the kinetics of electrochemical reactions by thin-layer voltammetry

Linear potential sweep voltammetry in thin layers of solution offers numerous advantages for the study of irreversible reactions. The experimental equations, derived here for representative reaction types, are simpler than their counterparts in ordinary voltammetry, and may in some cases be solved directly for the electrochemical rate parameters, k0 and αn0. Rate measurements in thin layers do not require that both members of the reactant couple be present initially in solution. The physical and mathematical simplicity of thin layer voltammetry may allow the otherwise impossible study of irreversible systems involving multiple reactants, multiple charge-transfer steps or complicated stoichiometry. Experiments in which the theory is verified and exploited for studies of fundamental interest will be described in subsequent communications.

Study of the kinetics of electrochemical reactions by thin-layer voltammetry: I. theory

Linear potential sweep voltammetry in thin layers of solution offers numerous advantages for the study of irreversible reactions. The experimental equations, derived here for representative reaction types, are simpler than their counterparts in ordinary voltammetry, and may in some cases be solved directly for the electrochemical rate parameters, k0 and αn0. Rate measurements in thin layers do not require that both members of the reactant couple be present initially in solution. The physical and mathematical simplicity of thin layer voltammetry may allow the otherwise impossible study of irreversible systems involving multiple reactants, multiple charge-transfer steps or complicated stoichiometry. Experiments in which the theory is verified and exploited for studies of fundamental interest will be described in subsequent communications.

Potential sweep voltammetry with uncompensated ohmic potential drop. irreversible charge transfer

Potential sweep voltammetry with uncompensated ohmic potential drop. irreversible charge transfer

Potential sweep voltammetry with uncompensated ohmic potential drop. Irreversible charge transfer

Summary Potential sweep voltammetric curves for a totally irreversible electrode process with uncompensated ohmic drop, when mass transfer takes place by semi-infinite linear diffusion, have been calculated. These curves have been used to derive operational diagrams that allow the evaluation of the electrochemical kinetic parameters. Experimental data obtained for the totally irreversible reduction of bromate ion at a mercury electrode have been examined in terms of the theory. The electrochemical kinetic parameters thus derived are in very good agreement with those reported in the literature.

A Controlled-Potential and Controlled-Current Cyclic Voltammeter†

SUMMARY An instrument has been designed and constructed to be used primarily for electrochemical investigations in molten salt systems. It operates in either a controlled-potential or controlled-current mode. In the controlled-potential mode it may be used for linear potential sweep voltammetry or chronoamperometry; in the controlled-current mode, for chronopotentiometry with control of the initial potential. Fast electronic switching circuitry permits reversal of the sweep direction or current polarity, or termination of the experiment at preselected electrode potentials. Easily implemented extensions of the basic operating modes are discussed. The potentiostat is designed to deliver 100 mA at ±10 V, but larger transient currents can be accommodated. Accurate, calibrated sweep rates of 0.005 to 500 V/sec make the instrument suitable for kinetics studies. The rapid sweep rates also are used to advantage to minimize the effects of convective mass transport.

On the Separation of Half-Wave Potentials Required for Resolution of Simple, Reversible, Overlapping Waves in Stationary Electrode Voltammetry

SUMMARY Linear potential sweep voltammetry at stationary or quasi-stationary electrodes has become a widely accepted analytical technique. In contrast with the well-known dc polarographic current-voltage curve which reaches a limiting current (i1) at potentials sufficiently removed from the half-wave potential (E1/2), the voltammetric curve at a stationary electrode in unstirred solution reaches a maximum value (ip) after which the current decreases rather slowly as the potential is increased further. This “tail” is a matter of concern in the analysis of multicomponent systems if two or more species react during a single sweep of the electrode potential. This communication presents the results of calculations made to determine the separation of half-wave potentials required to permit the quantitative determination of each species in multicomponent systems. Regular, first-, and second-derivative techniques are considered.

Potential-step electrolysis followed by linear-sweep voltammetry at a plane mercury-film electrode

A theoretical treatment is given of constant-potential electrolysis followed by linear potential-sweep voltammetry at a mercury-film electrode. The case of an oxidizing potential step followed by reduction with a linear sweep is considered, as well as that of a reducing potential step followed by oxidation with a linear sweep. The analytical aspects of the results are discussed. The effect of initial and boundary conditions on the continuity of the current-potential curve at the start of the potential sweep is considered.

Potential-sweep voltammetry: Theoretical analysis of monomerization and dimerization mechanisms

On the basis of a previously reported general theory of chemical polarization under the conditions of potential-sweep voltammetry, current/potential curves have been calculated for electrode processes involving dimerization of the charge-transfer product or formation of the depolarizer by dissociation of an electro-inactive species (monomerization). Very fast chemical reactions, very much displaced at the equilibrium towards the electro-inactive species have been considered. Diagnostic criteria characterizing these mechanisms have been derived and compared with those for other types of electrochemical reactions.

Linear potential-sweep voltammetry at a plane mercury- film electrode

A general treatment is given of linear potential-sweep voltammetry with a mercury-film electrode. The current-potential equations for both oxidizing and reducing potential-sweeps are considered. A mathematical approximation, useful for very thin mercury-films, is discussed, while the limiting case of zero film thickness is also considered. The effect of ohmic drop on the current-potential curves is given. The bearing of the results on experiment is pointed out.

Potential-step electrolysis followed by linear-sweep voltammetry

The method of potential-step electrolysis followed by linear potential-sweep voltammetry is considered theoretically. It is shown that, for a reversible electrode reaction without kinetic complications, the current—potential curve obtained during the linear potential-sweep is closely connected with the Ševčik—Randies P-function of normal linear-sweep voltammetry. Analytical implications are pointed out, while the presence of kinetic complications and the effect of finite electrode volume are briefly discussed.

Potential-sweep voltammetry—adsorption of chloranilic acid on a mercury electrode

The behaviour of chloranilic acid on mercury electrodes has been investigated by linear potential-sweep voltammetry. In very dilute solutions, a single adsorption peak appears. In more concentrated solutions, a second peak is observed which is diffusion-controlled. The amount of chloranilic acid adsorbed at the different concentrations has been determined by extrapolation, from the plots of the integrals of the current-potential curves versus the reciprocal of the square-root of potential-sweep rate. The maximum surface coverage thus derived is in very good agreement with the surface excess obtained from measurement of the mercury-solution interface tension using the drop-weight method. The results are consistent with the hypothesis of the formation of a monolayer of chloranilic acid with a flat orientation of the molecule with respect to the electrode surface.

Linear Potential Sweep Voltammetry in Thin Layers of Solution.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLinear Potential Sweep Voltammetry in Thin Layers of Solution.A. T. Hubbard and F. C. AnsonCite this: Anal. Chem. 1966, 38, 1, 58–61Publication Date (Print):January 1, 1966Publication History Published online1 May 2002Published inissue 1 January 1966https://doi.org/10.1021/ac60233a015RIGHTS & PERMISSIONSArticle Views491Altmetric-Citations149LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (407 KB) Get e-Alerts Get e-Alerts