Composite carbon electrode with a coating of nanostructured, reduced graphene oxide for water electrodialysis

Abstract Electrodialysis (ED) and electrodeionization (EDI) are the new methods that are being used in water desalination processes. Reliable, electrochemically stable and efficient electrodes are the crucial components of the ED/EDI electrodialysers. The article proposes a new material for electrodes in electromembrane desalination systems. Graphene composite electrodes were created by bonding carbon fibres with epoxy resin and then coated with a layer of nanostructured, reduced graphene oxide. The graphene electrode material underwent electrochemical characterization by cyclic voltammetry, electrochemical impedance spectroscopy and potentiostatic polarization techniques. FTIR and Raman spectroscopy were used to determine the material’s chemical structure. The change in the surface morphology and elemental composition of the electrodes after fabrication and exploitation of the composite was studied by SEM and EDS. The electrodes were used successfully in multi-electrode electrodialysis devices, resulting in a desalination rate of over 90%. The electrodes were proven to be functional and durable. It was also confirmed that the oxidation/reduction phenomena on the electrode surfaces were fully reversible after changing their polarization, which was used cyclically to clean the electrodialyser. The parameters obtained indicate that this material can also be successfully used in other electrode processes. Graphical Abstract