Magnetic-field-induced Fe₃O₄@CNTs/PES/SPSf composite membrane for efficient removal of methylene blue by adsorption and catalytic degradation

Novel composite membranes are successfully developed for adsorption and catalytic degradation of methylene blue (MB) by blending Fe3O4-coated CNTs (Fe3O4@CNTs) nanoparticles in polyethersulfone (PES) and sulfonated polysulfone (SPSf) matrix via nonsolvent-induced phase separation (NIPS) method assisted by magnetic field. Fe3O4@CNTs nanoparticles migrate to the separation layer under the induction of magnetic field, thus Fe3O4@CNTs/PES/SPSf composite membranes prepared under magnetic field exhibit a better dye removal ability compared with that without magnetic field. The MB removal ratio by Fe3O4@CNTs/PES/SPSf composite membrane containing 8 wt% Fe3O4@CNTs (M2-M) can reach up to 99% in 30 min under the conditions of 0.25 g composite membrane, 20 mg/L MB, 0.1 mol/L H2O2, pH = 3 and 80 degrees C. Furthermore, the composite membranes show excellent recycling performance, as the MB removal capacity remains at 99% even after four cycles.