A Self-cleaning, catalytic titanium carbide (MXene) membrane for efficient tetracycline degradation through peroxymonosulfate activation: Performance evaluation and mechanism study

Innovative integration of advanced oxidation processes (AOPs) and membrane separation can achieve efficient recycling of catalysts and membrane anti-fouling. In this study, a catalytic, self-cleaning Co2+/MXene (CM) membrane with low Co2+ content (0.2 wt%) was engineered and fabricated using a facile metal ion-initiated gelation approach. The CM membrane exhibited a rapid and high removal efficiency (>97% within 5 min) for tetracycline (TC) in the presence of peroxymonosulfate (PMS). Moreover, the TC removal efficiency was also investigated under different experimental conditions. The self-cleaning capacity of the CM membrane was assessed by filtration of bovine serum albumin (BSA), showing that the CM membrane had a higher flux retention ratio (FRR) with peroxymonosulfate (PMS) (52%) than without PMS (22%). Fouling modelings indicated that the cake layer fouling became the primary parameter responsible for the permeability reduction in CM/PMS/BSA filtration. Quenching experiments and electron spin resonance (ESR) spectrum analysis revealed that sulfate radicals (•SO4-) and hydroxyl radicals (•OH) jointly contributed to the catalytic and anti-fouling properties of the CM membrane. This study exemplifies a novel, time-saving strategy for the preparation of a catalytic, self-cleaning membrane capable of efficient wastewater remediation with membran anti-fouling properties.