potensiostat

A potentiostat is an electronic instrument used in electrochemistry to control the electric potential of a working electrode relative to a reference electrode and to measure the current flowing in the cell. It is a central tool for studying redox reactions and electrochemical processes.

In a typical three-electrode setup, a working electrode, a reference electrode, and a counter (or auxiliary) electrode are immersed in an electrolyte. The potentiostat applies a potential to the working electrode by driving current between the working and counter electrodes, while the reference electrode provides a stable potential reference.

Potentiostats can operate in potentiostatic (voltage-control) mode, and many instruments can also function as galvanostats (current-control). They enable techniques such as cyclic voltammetry, chronoammetry, chronopotentiometry, amperometry, and, when combined with specialized hardware, electrochemical impedance spectroscopy. They are used in battery research, corrosion testing, electroplating, sensors, and materials science.

Key performance parameters include the potential window, scan rate, current range, accuracy and stability of the reference electrode, noise, and response time. Modern units range from benchtop systems to compact handheld devices, often with software for data acquisition, analysis, and experiment control.

Potentiostats have evolved from laboratory instruments to essential tools in research and industry, enabling precise control and measurement of electrochemical processes across chemistry, materials science, and biotechnology.