Etymology and History of Electrolysis - The term 'electrolysis' was introduced by Michael Faraday in 1834. - The word is derived from the Greek words ἤλεκτρον and λύσις, meaning amber and dissolution, respectively. - William Nicholson and Anthony Carlisle observed the production of hydrogen and oxygen through electrolysis in the early 19th century. - Martin van Marum unknowingly produced electrolysis in 1785 while using an electrostatic generator to reduce tin, zinc, and antimony. - Luigi Galvani's experiments with frog legs led to Alessandro Volta's tests on the generation of electricity through dissimilar metal sheets. - Humphry Davy conducted preliminary experiments on electrolysis and hypothesised the release of electrical energy during the formation of compounds. - Johan August Arfwedson discovered lithium in 1817, and William Thomas Brande used electrolysis to isolate it in 1821.

Overview and Process of Electrolysis - Electrolysis involves the passing of a direct electric current through an electrolyte, resulting in chemical reactions and decomposition. - The main components required for electrolysis are an electrolyte, electrodes, and an external power source. - An ion-exchange membrane or salt bridge can be used as a partition to prevent diffusion of products. - The electrolyte contains free ions and conducts electric current. - Electrodes can be made of metal, graphite, or semiconductor materials, depending on reactivity and cost. - Electrolysis involves the interchange of atoms and ions through the removal or addition of electrons. - The desired products of electrolysis are often in a different physical state from the electrolyte and can be separated mechanically. - The quantity of products is proportional to the applied current. - Faraday's laws of electrolysis state that the products produced in electrolytic cells connected in series are proportional to their equivalent weight. - Positively charged ions (cations) move towards the cathode, while negatively charged ions (anions) move towards the anode.

Variations and Applications of Electrolysis - Pulsating current leads to different products compared to DC. - Pulsing increases the ratio of ozone to oxygen produced in electrolysis of aqueous acidic solutions. - Electrolysis of ethanol with pulsed current evolves an aldehyde instead of an acid. - Galvanic cells and batteries use redox reactions to generate electrical potential. - Secondary batteries can be considered as electrolytic cells when charged. - Hall-Héroult process is used for producing aluminium. - Electrometallurgy is used for producing various metals such as lithium, sodium, and potassium. - Chloralkali process is used for producing chlorine and sodium hydroxide. - Electrofluorination is used for producing perfluorinated organic compounds. - Electrolysis is used for purifying copper, producing fuels like hydrogen, and removing rust.

Research Trends in Electrolysis - Electrolysis of carbon dioxide can produce value-added chemicals such as methane, ethylene, and ethanol. - Electrolysis of acidified water produces hydrogen and oxygen in a 2:1 ratio. - Carbon/hydrocarbon assisted water electrolysis (CAWE) process utilizes carbon or hydrocarbon to reduce energy input in hydrogen generation. - Electrocrystallization is a specialised application of electrolysis used to obtain conductive crystals. - Electrolysis of iron ore can eliminate direct emissions in steel production if electricity is created from green energy.

Electrolysis of Seawater - Direct electrolysis of seawater has been investigated as a method for hydrogen generation. - Different electrolysis technologies, including alkaline electrolysis and proton-exchange membrane electrolysis, have been studied. - Proton-exchange membrane electrolysis offers a suitable combination of economic operation costs, environmental considerations, and safety. - Solid oxide electrolysers require high temperatures to operate but suffer from degradation when turned off. - Multiple-criteria decision analysis has been used to evaluate the performance of different electrolysis methods.