Electrolysis is a technique that uses direct electric current to drive an otherwise non-spontaneous chemical reaction. It is a process of decomposing ionic compounds into their elements by passing a direct electric current through the compound in a fluid form. The process is carried out in an electrolytic cell, which is an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions. The substance to be transformed may form the electrode, may constitute the solution, or may be dissolved in the solution. The voltage that is needed for electrolysis to occur is called the decomposition potential. The word "lysis" means to separate or break, so in terms, electrolysis would mean "breakdown via electricity". Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell.
Electrolysis is used in various applications, including:
- Electroplating: The process of coating a metal object with a thin layer of another metal by electrolysis.
- Electrolytic refining: The process of refining metals such as copper, zinc, and tin by electrolysis.
- Electrolysis of water: The process of splitting water into hydrogen and oxygen gas by passing an electric current through it.
- Electrolysis hair removal: A method of removing individual hairs from the face or body by destroying the growth center of the hair with chemical or heat energy.
Electrolysis is a tool to study chemical reactions and obtain pure elements. The word "electrolysis" was introduced by Michael Faraday in 1834, using the Greek words ἤλεκτρον "amber", which since the 17th century was associated with electrical phenomena, and λύσις meaning "dissolution".
