elektroliza

Elektroliza, or electrolysis, is a chemical process that uses electrical energy to drive a non-spontaneous redox reaction. In an electrolytic cell, a direct current source pushes electrons from one electrode to the other through an electrolyte, causing chemical changes at the electrodes.

The electrolyte provides mobile ions; it can be a molten salt or an aqueous solution. The two electrodes are called the anode (where oxidation occurs) and the cathode (where reduction occurs). The external voltage supplies energy to overcome the natural redox tendency and to force electron transfer. Faraday's laws relate the amount of material deposited or released to the total electric charge passed.

Common examples: the electrolysis of molten sodium chloride produces sodium metal at the cathode and chlorine gas at the anode; the electrolysis of water yields hydrogen at the cathode and oxygen at the anode; in brine electrolysis, chlorine gas and sodium hydroxide may be produced together under appropriate conditions.

Industrial applications include the chlor-alkali process for chlorine and sodium hydroxide production; the Hall–Héroult process for aluminum refining; electroplating, electrorefining of metals, and wastewater treatment. The method is energy-intensive and depends on electrode materials and electrolyte stability. Gas evolution and corrosion are safety and design considerations.

Historically, electrolysis contributed to the development of electrochemistry; Faraday formulated the laws governing the relationship between electric charge and product formation in the 1830s.