Cyclic Voltammetry: Roles of Working, Auxiliary, Ref. Electrodes & Potentiostat

[higherme]

I'm trying to find out the roles of the following for cyclic voltammetry:
working electrode
auxiliary electrode
reference electrode
and potentiostat

I kind of found out what they are.. but i am not sure of its exact role, like for the working electrode, it is the electrode at which the redox reaction of interest occurs, but what does it actually do, and what happens there.

any one can give me any sites, I've tried google many times but didn't find much

Thanks a lot!

 

[Gokul43201]

http://www.currentseparations.com/issues/14-2/cs14-2d.pdf

But if you have fundamental queries, you should probably start here: http://www.prenhall.com/settle/chapters/ch37.pdf

 

[Blueshift5]

Cyclic voltammetry is a powerful electrochemical technique used to study redox reactions and measure the kinetics and thermodynamics of electrochemical processes. In this technique, a voltage is applied to an electrochemical cell containing the analyte of interest, and the resulting current is measured. The voltage is then varied in a cyclic manner, and the corresponding current is recorded. This technique provides information about the redox behavior of the analyte, such as its oxidation and reduction potentials, as well as its electron transfer rate.

The working electrode is a key component in cyclic voltammetry and plays a crucial role in the technique. It is the electrode at which the redox reaction of interest occurs. This electrode is typically made of a conductive material, such as platinum, gold, or glassy carbon, and is in direct contact with the analyte. The working electrode serves as the site for the electrochemical reaction to take place and allows for the flow of electrons between the analyte and the electrode.

The auxiliary electrode, also known as the counter electrode, is another important component in cyclic voltammetry. Its role is to complete the electrical circuit by providing a pathway for the current to flow. This electrode is typically made of an inert material, such as platinum, and is not in direct contact with the analyte. Its main function is to balance the current at the working electrode and maintain a constant potential during the experiment.

The reference electrode is used to establish a known potential against which the working electrode potential can be measured. It is typically made of a stable and reversible redox couple, such as a silver/silver chloride electrode, and is in contact with the electrolyte solution. The reference electrode ensures that the potential at the working electrode is accurately measured and provides a reference point for the electrochemical reactions to take place.

Lastly, the potentiostat is the instrument used to control the voltage applied to the electrochemical cell and measure the resulting current. It maintains a constant potential between the working and reference electrodes, and also allows for the voltage to be varied in a cyclic manner. The potentiostat is essential for accurate and precise measurements in cyclic voltammetry.

In summary, the working electrode is where the electrochemical reaction takes place, the auxiliary electrode completes the electrical circuit, the reference electrode provides a known potential, and the potentiostat controls the voltage and measures the current. These components work together to make cyclic voltammetry a powerful technique for studying redox reactions