Electrochemically\nAssisted Cobalt/MXene Membrane for\nEffective Water Treatment: Synchronously Improving Catalytic Performance\nand Anti-Interference Ability

Catalytic membrane technology for water treatment is\noften constrained\nby a trade-off between permeability and catalytic efficiency as well\nas interference from coexisting anions and organic matter in natural\nwater matrices. Herein, a novel cobalt-loaded MXene (Co/MXene) 2D\nmembrane with good hydrophilicity, electrical conductivity, and PMS\nactivation function is constructed. The negative voltage is exerted\non the membrane to significantly enhance its PMS activation efficiency\nand anti-interference capacity toward effective water treatment. Under\n−2 V, the optimal Co/MXene catalytic membrane displays 100%\nrhodamine b (RhB) removal within a residence time of only 1.1 s, whose\nRhB degradation kinetic constant (<i>k</i> of 6.85 s<sup>–1</sup>) is 17.6 times higher than that of the Co/MXene catalytic\nmembrane alone and is also greatly superior to other advanced catalysts\nand catalytic membranes. Meanwhile, the catalytic membrane displays\nobvious anti-interference ability in the presence of various coexisting\nsubstances of the water matrix and performs well in treating the secondary\neffluent of coking wastewater. The radical-dominated (SO<sub>4</sub><sup>•–</sup> and •OH) mechanism accompanied\nby the nonradical species (<sup>1</sup>O<sub>2</sub> and Co(VI)O)\nis revealed in the system, and the reactive species production is\nobviously enhanced under negative voltage. Experimental results and\ntheoretical calculations jointly confirm the key role of electrochemical\nassistance in enhancing membrane performance, which not only facilitates\ncycling of Co<sup>3+</sup>/Co<sup>2+</sup> for enhanced PMS activation\nvia improving PMS adsorption and promoting charge transfer from Co\nto PMS but also hinders interference from coexisting substances in\nwater via electrostatic repulsion.