In electrochemical analysis, electrodes are essential because they allow electron transfer between the chemical species in a solution and the external circuit. They basically act as sites where reactions happen.
Here’s a explanation:
1. Types of Electrodes
- Working Electrode – The main electrode where the chemical reaction of interest (oxidation or reduction) occurs.
- Reference Electrode – Provides a stable and known voltage so we can measure the potential of the working electrode accurately.
- Counter (Auxiliary) Electrode – Completes the electrical circuit, allowing current to flow through the solution.
2. Roles of Electrodes
- Working Electrode: Detects the analyte by allowing it to gain or lose electrons. The current generated tells us about the analyte’s concentration or behavior.
- Reference Electrode: Acts like a fixed point to compare the potential of the working electrode.
- Counter Electrode: Ensures that the current can flow, so the reaction at the working electrode can proceed smoothly.
3. Importance
- Electrodes enable redox reactions to happen at the solution-surface interface.
- They allow precise measurement of current and potential, which is the basis of electrochemical analysis.
- Different electrodes are chosen depending on the type of analysis (e.g., biosensors, voltammetry, amperometry).
In simple words: Electrodes are like “reaction platforms” and “measuring points” in electrochemical analysis—they let reactions happen and let us measure them.