Electrodeposition of electrocatalytic coatings in systems based on deep eutectic solvents: a review

This review systematizes literature data on the use of electrochemical systems based on the novel generation of ionic liquids, deep eutectic solvents, for electrodeposition of coatings exhibiting improved electrocatalytic properties. It is shown that most published works on the topic are connected with deposition of coatings based on noble metals and iron family metals as well as their alloys and composites. The main advantages of the use of deep eutectic solvents for electrochemical synthesis of electrocatalysts are as follows: the possibility to prepare nanostructured coatings having compositions, structures and surface morphologies that cannot be achieved when using water electrolytes (including deposition of very electronegative metals); the size- and shape-controlled synthesis of deposited nanocrystals, which ensures improved electrocatalytic behavior; no need to use toxic and expensive additives, stabilizers, precursors, surfactants, etc.; and environmental issues (low hazard and fast biodegradability of the constituents of deep eutectic solvents). The prospects of creation of new high-efficient electrocatalytic coatings from electrolytes based on deep eutectic solvents are considered.