Redox electrode is an electrode made from electron conductive material and characterized by high chemical stability in studied solutions. It uses for potentiometric aims (measuring of redox potential of a specific redox system in solution) and for electrochemical studies (investigation of electrochemical kinetics of interfacial processes).

Correlation of an electrode potential and redox system composition can be realized by Nernst equation:
Ox + e^- = Red
, where
E⁰ - standard potential of a specific redox system,
R - gas constant,
T - temperature in Kelvin degree,
n - number of electron taking part in a specific redox reaction,
F - Faraday constant
a_Ox, a_Red - activity of oxidative and reductive participances of redox reaction.

There are two general class of redox electrodes:

• metal (most common are Pt electrode and Au electrode , but for specific aims other material (Ti, Ir) can be used)
• semi-conductors (most common are graphite electrode , diamond electrode , SnO₂ )