Voltammetric Sizing of Inert Particles

• Published in: Chemphyschem Vol. 6; no. 7; pp. 1340 - 1347
• Main Authors: Davies, Trevor J., Lowe, Eleanor R., Wilkins, Shelley J., Compton, Richard G.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 11-07-2005; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; diffusion domains; electrochemical analysis; Electrochemistry; Exact sciences and technology; General and physical chemistry; modified electrodes; Study of interfaces; voltammetry; Electrodes; Particle; Cyclic voltammetry; Particle size; diffusion domains; Electrochemistry; Measurement method; Sizing; Diffusion; Alumina; Potassium chloride; electrochemical analysis, electrochemistry ,modified electrodes, voltartwietry
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.200500152

The average size of inert particles is determined using a simple electrochemical procedure. Alumina particles are deposited on an edge‐plane graphite electrode, and a cyclic voltammogram is recorded. The scan rate employed varies between 0.2 and 2 V s−1. At these scan rates the diffusion layer thickness is greater than the size of the alumina particles, minimizing the influence of the particles′ height on the observed voltammetry. The average size of the particles is determined via comparison of the experimental voltammograms with simulations.
A good measure! When inert particles are placed on an electrode surface, the cyclic voltammetric response of the resulting modified electrode is found to be dependent on the size and shape of the particles. Therefore, by analysing the voltammetric response of the modified electrode with the appropriate theoretical model, it is possible to deduce information regarding the size and shape of the particles on the electrode surface (see figure).