Innovating Electrosynthesis From Metal Electrodeposition to Organic Chemistry: Deep Eutectic Solvents as Efficient and Sustainable Media.

Electrosynthesis is an ideal tool for achieving effective processes across various domains of organic and inorganic chemistry, while ensuring environmental and economic sustainability. However, due to the requirement of a conductive reaction medium, supporting electrolytes are needed in organic solvents or water. Furthermore, the nature of the solvent itself can constitute an issue, as volatile organic compounds can pose operational safety risks, their electrochemical stability can be limited, and their production mainly relies on fossil sources. The use of aqueous media is instead limited due to reagents' solubility and potential interferences due to the reactivity of water. A valuable and innovative alternative to conventional solvents is represented by hydrogen bond acceptor-donor mixtures known as deep eutectic solvents (DESs). These systems are characterized by a liquid phase that exhibits a certain degree of supramolecular organization, have conductive nature, and their physicochemical properties are easily tuneable through engineering of chemical composition. In this review, we highlight advances in the use of DESs in electrosynthesis, from electro-organic transformations to the preparation of metal nanoparticles and inorganic nanomaterials highly useful as electrocatalysts, with a critical focus on how these systems impact both the sustainability aspects and synthetic outcomes of the reported procedures.