Enhanced selectivity of reactive intermediates by modifying electrodes with layered materials for the green high-salinity wastewater treatment

Abstract

Improving the selectivity of the reactive intermediates such as ${\mathrm{ClO}}^{-}$ and $•\mathrm{OH}$ by modifying nickel foam electrodes with ion exchangeable layered materials would greatly enhance the efficiency of high-salinity wastewater treatment. A universal pattern was verified herein that through functioning as a permeable overlayer regulating the transport of cations/anions, ${\mathrm{ClO}}^{-}$ and $•\mathrm{OH}$ could be the predominant intermediates in the anionic/cationic layered material modified electrode. The significance of selectivity enhancement includes improving electrochemical efficiency and reducing the usage of chemical reagents. For instance, it is demonstrated that electrochemically degrading high salinity azo wastewater using decorated electrodes would be as effective as chemical treatment. Furthermore, electrochemical oxidation using cation layered material modified electrode could reduce the pKa of the oxidized cellulose filter paper as effectively as using ${H_{2}O}_2$.