A coupled molybdenum disulfide - copper modification of NF membrane for enhanced anti-bacterial performance

Biofouling is a bottleneck in restricting nanofiltration (NF) application for drinking water treatment. In current study, we reported a novel molybdenum disulfide (MoS2) ‑ copper (Cu2+) modification of polyamide NF membrane for enhanced anti-bacterial performance. The incorporation of Cu2+ into the separation layer through interfacial polymerization was to enhance the anti-microbial ability, while the introduction of lamellar MoS2 into the polyamide active layer was to stably immobilize copper, as well as to provide an interlayer nanochannels for water transport and also to enhance membrane hydrophilicity. The resultant membrane showed an excellent anti-bacterial ability, with 99.1% and 96.7% inactivation efficiencies of Escherichia coli and Bacillus subtilis, respectively, at MoS2 - Cu molar ratio of 1:0.3. Compared to the control membrane, the obtained membrane exhibited a 44% increase of pure water flux. Membrane stability assessment indicated that > 93% of initial loaded Cu2+ and Mo4+ remained in the membrane matrix after a 5-d shaking test. Membrane characterization suggested that the MoS2 - Cu complexes were uniformly dispersed into the membrane active layer, which led to an increased membrane roughness that was favorable for antibiofouling. Overall, the facile MoS2 – Cu addition with intensified anti-biofouling ability created in this study provides a promising membrane modification approach for practical application.