Nanofluids and Ionic Fluids as Liquid Electrodes: An Overview on Their Properties and Potential Applications

Abstract

The current review work focuses on recent developments in the exploration of electroactive nanofluids, ionanofluids, and ionic liquids acting as liquid electrodes. The nanofluids used for this purpose are composed of organic or aqueous electrolytes as base fluids with the addition of nanoparticles in pure, oxidized, or hybrid forms. On the other hand, the ionic liquids are formed by adding a solution, which can be an acid, a base, or a salt, in water. The electrochemical properties, such as electrical conductivity and capacitance, of these innovative fluids are discussed thoroughly, along with their influencing factors, such as the nature and concentration of the included nanoparticles, the type of base fluids, and the operating temperature. Moreover, this overview summarizes the fundamental applications of electroactive nanofluids, ionanofluids, and ionic liquids in various possible flow-cell configurations and electrolysis methods, along with the associated feasibility factors. Additionally, this survey of scientific papers on the matter enabled the listing and evaluation of general aspects related to the usage of electroactive nanofluids, ionanofluids, and ionic liquids. Finally, it addresses the main problems associated with such types of fluids and outlines the primary prospects for further research and utilization of electroactive nanofluids, ionanofluids, and ionic liquids in diverse scientific and technological fields.