Randles–Ševčík Equation
Last Updated: 10/27/20 by Random Electrochemist
ARTICLE TAGS
1Randles-Ševčík Equation
There are many resources that describe the detailed background, derivation, and applications of the Randles-Ševčík equation.
Bard, A. J.; Faulkner, L. A. Electrochemical Methods: Fundamentals and Applications, 2nd ed. Wiley-Interscience: New York, 2000.
Kissinger, P.; Heineman, W. R. Laboratory Techniques in Electroanalytical Chemistry, 2nd ed. Marcel Dekker, Inc: New York, 1996.
Wang, J. Analytical Electrochemistry, 3rd ed. John Wiley & Sons, Inc.: Hoboken, NJ, 2006.
Langhus, D. L. Fundamentals of Electroanalytical Chemistry. J. Chem. Educ., 2002, 79(10), 1207.
Elgrishi, N.; Rountree, K. J.; McCarthy, B. D.; Rountree, E. S.; Eisenhart, T. T.; Dempsey, J. L. A Practical Beginner’s Guide to Cyclic Voltammetry. J. Chem. Educ., 2018, 95(2), 197-206. Here, we present just a snippet to get you started.
Bard, A. J.; Faulkner, L. A. Electrochemical Methods: Fundamentals and Applications, 2nd ed. Wiley-Interscience: New York, 2000.Kissinger, P.; Heineman, W. R. Laboratory Techniques in Electroanalytical Chemistry, 2nd ed. Marcel Dekker, Inc: New York, 1996.
Wang, J. Analytical Electrochemistry, 3rd ed. John Wiley & Sons, Inc.: Hoboken, NJ, 2006.
Langhus, D. L. Fundamentals of Electroanalytical Chemistry. J. Chem. Educ., 2002, 79(10), 1207.
Elgrishi, N.; Rountree, K. J.; McCarthy, B. D.; Rountree, E. S.; Eisenhart, T. T.; Dempsey, J. L. A Practical Beginner’s Guide to Cyclic Voltammetry. J. Chem. Educ., 2018, 95(2), 197-206. Here, we present just a snippet to get you started.
In a voltammetric experiment where a potential sweep is applied to the working electrode using a potentiostat (e.g., LSV
Linear Sweep Voltammetry (LSV)
or CV
Cyclic Voltammetry (CV)
), the peak current 
observed for a voltammogram follows the Randles-Ševčík equation,
Linear Sweep Voltammetry (LSV)
or CV
Cyclic Voltammetry (CV)
), the peak current observed for a voltammogram follows the Randles-Ševčík equation,
where 
is Faraday's constant, 
is the universal gas constant, 
is the absolute temperature, 
is the number of electrons involved in the redox half-reaction being studied, 
is the diffusion coefficient for the redox active species, 
is the molar concentration of the redox active species, 
is the surface area of the electrode, and 
is the rate at which the potential is being swept.
is Faraday's constant, is the universal gas constant, is the absolute temperature, is the number of electrons involved in the redox half-reaction being studied, is the diffusion coefficient for the redox active species, is the molar concentration of the redox active species, is the surface area of the electrode, and is the rate at which the potential is being swept.The Randles-Ševčík equation is often written in an abbreviated form under the assumption that the temperature is fixed at 298.15 K (25℃). For work at this particular temperature, the constants appearing at the beginning of the equation can be combined, allowing the equation to be written more simply as follows:
The constant appearing at the beginning of this simplified version of the equation is understood to have units (e.g., 2.69 × 105 C mol-1V-1/2).
2References
- Bard, A. J.; Faulkner, L. A. Electrochemical Methods: Fundamentals and Applications, 2nd ed. Wiley-Interscience: New York, 2000.
- Kissinger, P.; Heineman, W. R. Laboratory Techniques in Electroanalytical Chemistry, 2nd ed. Marcel Dekker, Inc: New York, 1996.
- Wang, J. Analytical Electrochemistry, 3rd ed. John Wiley & Sons, Inc.: Hoboken, NJ, 2006.
- Langhus, D. L. Fundamentals of Electroanalytical Chemistry. J. Chem. Educ., 2002, 79(10), 1207.
- Elgrishi, N.; Rountree, K. J.; McCarthy, B. D.; Rountree, E. S.; Eisenhart, T. T.; Dempsey, J. L. A Practical Beginner’s Guide to Cyclic Voltammetry. J. Chem. Educ., 2018, 95(2), 197-206.
