Modified multi-walled carbon nanotube and silanized MXene electrostatic assembly enables antimicrobial, conductive Mixed Matrix Membranes for efficient electrochemical cleaning

Ultrafiltration membranes have significant potential for application in wastewater treatment. However, membrane fouling seriously affects the separation efficiency and service life of the membrane. The preparation of conductive membranes offers a novel idea for removing membrane fouling. In this work, polyethersulfone (PES) mixed matrix membranes containing epigallocatechin gallate-modified multi-walled carbon nanotubes and silanized MXene were simply prepared by nonsolvent-induced phase inversion. Due to the introduction of a three-dimensional network structure electrostatically assembled with the two nanomaterials, the membranes have a great potential for balancing permeability, separating ability, and electrical conductivity. In addition, due to the presence of two kinds of fillers, the modified membrane also showed excellent electrical conductivity and antimicrobial performance, with a conductivity of up to 6.4 mS/cm, while exhibiting an ultra-high bacterial inhibition rate of close to 100%. More importantly, through electrochemically assisted cleaning, the membrane fouling was efficaciously removed by nanobubbles and electrostatic force, and the flux recoveries after membrane filtration of CR and BSA reached 93.1% and 91.7%, respectively. In summary, the composite membrane has lots of promise for use in the purification of wastewater due to its considerable pollution removal effect and long-term operational performance.