Is Voltammetric Current Proportional to the Number of Transferred Electrons for Multi-Charged Ions or to 3/2 Power of the Number?
✍ Scribed by Koichi Aoki
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 111 KB
- Volume
- 17
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
Abstract
Particles with a large number of electrons to transfer, such as nanoparticles and colloidal redox particles, give voltammetrric currents that were demonstrated theoretically to be proportional directly to the number of the electrons, n, rather than to n^3/2^. The latter quantity is included in the conventional expression for voltammetric peak currents of multi‐charge transfer processes. This apparent contradiction appears depending on whether the charge transfer occurs concurrently (n^3/2^) or consecutively (n). The expression for the linear sweep voltammetric current was derived from a combination of the diffusion equation for large particles with n electrons and the Nernst equation for the n‐time consecutive one‐electron reactions at the electrode. The power in n for the peak currents, in several voltammetric techniques, was demonstrated to be ascribed to the convolution of the Nernst equation and the diffusion equation.