S'identifier

Voltammetry is an electroanalytical technique in which the current flowing through an electrochemical cell is measured as a function of applied potential, typically under conditions of concentration polarization. The technique provides valuable information about redox-active species, and the current response is plotted as a voltammogram.

A voltammetric cell uses three electrodes: a working electrode, a reference electrode, and an auxiliary electrode. The redox reactions occur in the working electrode, and a potentiostat controls its potential. Mercury electrodes are frequently used as working electrodes due to their wide negative potential range, which minimizes interference from hydrogen evolution. Mercury electrodes can form amalgams with various metals, enhancing certain redox reactions. In addition, their surface can be renewed by forming new drops, maintaining accuracy. Common types include the hanging mercury drop electrode (HMDE) and the dropping mercury electrode (DME).

The reference electrode, such as the saturated calomel electrode or silver-silver chloride electrode, plays a crucial role in voltammetry. It maintains a constant potential, ensuring accurate measurement. The auxiliary electrode, often a platinum wire, completes the circuit.

Mercury electrodes are preferred in many applications due to their large negative potential range, which prevents unwanted hydrogen reduction, and their ability to form amalgams. Their versatility and the ability to renew the electrode surface ensure consistent and reliable results during measurements.

Voltammetry is widely applied in environmental monitoring (e.g., detecting trace metals), pharmaceutical analysis, and electrochemical sensor development. By analyzing the current response, voltammetry helps determine the concentration of electroactive analytes in the solution. In dilute solutions, the current reaches a limiting value directly proportional to the analyte's concentration, making this technique highly valuable for quantitative analysis.

Du chapitre 10:

article

Now Playing

10.17 : Voltammetry: Overview

Electrochemical Analyses and Redox Titration

163 Vues

article

10.1 : Electrochemistry: Overview

Electrochemical Analyses and Redox Titration

438 Vues

article

10.2 : Electrodes: Overview

Electrochemical Analyses and Redox Titration

261 Vues

article

10.3 : Interfacial Electrochemical Methods: Overview

Electrochemical Analyses and Redox Titration

176 Vues

article

10.4 : Potentiometry: Overview

Electrochemical Analyses and Redox Titration

360 Vues

article

10.5 : Potentiometry: Types of Electrodes

Electrochemical Analyses and Redox Titration

337 Vues

article

10.6 : Potentiometry: Membrane Electrodes

Electrochemical Analyses and Redox Titration

274 Vues

article

10.7 : Redox Titration: Overview

Electrochemical Analyses and Redox Titration

332 Vues

article

10.8 : Redox Titration: Iodimetry and Iodometry

Electrochemical Analyses and Redox Titration

575 Vues

article

10.9 : Redox Titration: Other Oxidizing and Reducing Agents

Electrochemical Analyses and Redox Titration

172 Vues

article

10.10 : Potentiometric Titration: Overview

Electrochemical Analyses and Redox Titration

378 Vues

article

10.11 : End Point Prediction: Gran Plot

Electrochemical Analyses and Redox Titration

147 Vues

article

10.12 : Electrogravimetric Analysis: Overview

Electrochemical Analyses and Redox Titration

141 Vues

article

10.13 : Coulometry: Overview

Electrochemical Analyses and Redox Titration

124 Vues

article

10.14 : Controlled-Potential Coulometry: Electrolytic Methods

Electrochemical Analyses and Redox Titration

91 Vues

See More

JoVE Logo

Confidentialité

Conditions d'utilisation

Politiques

Recherche

Enseignement

À PROPOS DE JoVE

Copyright © 2025 MyJoVE Corporation. Tous droits réservés.