Potentiostats

A potentiostat is an electronic instrument used in electrochemistry to control the potential of a working electrode relative to a reference electrode while measuring the current flowing in the cell. It serves as the core device that enables precise electrochemical control and data collection during various analytical and synthetic procedures.

In a typical three-electrode arrangement, the working electrode is the site of the redox reaction, the reference electrode provides a stable reference potential, and the counter electrode completes the circuit. The potentiostat uses a feedback loop to adjust the potential of the working electrode by driving current through the counter electrode so that the potential follows a user-defined value relative to the reference electrode. The resulting current is measured and recorded, providing information about reaction kinetics, diffusion, and interfacial processes.

Modern potentiostats are capable of supporting a range of electrochemical techniques. Common methods include cyclic voltammetry, chronoamperometry, chronopotentiometry, differential pulse voltammetry, and square-wave voltammetry. Electrochemical impedance spectroscopy (EIS) also relies on a potentiostat to apply small AC perturbations around a bias potential. In addition to research settings, portable and compact potentiostats are used for field measurements and routine analysis.

Applications span corrosion testing, energy storage research (batteries and supercapacitors), sensors and biosensors, electroplating and electrodeposition, and various electrochemical syntheses. While primarily a voltammetric instrument, the potentiostat’s performance can be affected by electrode stability, solution resistance, and cell design, which influence the accessible potential window and data interpretation.