Efficient PEDOT Electrode Architecture for Continuous Redox-Flow Desalination

Both low-energy consumption and high salt removal rate are highly required in the electrochemical desalination. In this work, a conducting polymer poly(3,4-ethylene-dioxythiophene), i.e., PEDOT, is electrochemically decorated on a graphite foil as an electrode material of redox-flow desalination (RFD). At a current density of 2 mA·cm–2, the energy consumption of the RFD is reduced to 38.1 kJ·mol–1 with PEDOT-modified electrodes, compared with 154.5 kJ·mol–1 using a bare graphite electrode. Meanwhile, the salt removal rate is enhanced to 1.54 μmol·cm–2·min–1 using the PEDOT electrode from 1.11 μmol·cm–2·min–1 in the bare graphite electrode. The PEDOT electrodes can also provide excellent cycling stability. The improved performance may be due to the promising conductivity and porous structure of PEDOT, which would supply more active sites between the electrode and the redox electrolyte. The current research provides an electrochemical desalination strategy with low energy consumption and high salt removal rate, which is significant for the development of RFD technology.