Fabrication of antibacterial and self-cleaning CuxP@g-C3N4/PVDF-CTFE mixed matrix membranes with enhanced properties for efficient ultrafiltration

Despite membrane separation technology has been extensively implemented in various field, the fouling caused by bacterial and organic dye seriously impair the performance and lifespan of the membrane, the anti-fouling modification of the membrane is still a challenging. In this work, the antibacterial and self-cleaning poly (vinylidene fluoride-chlorotrifluoroethylene) (PVDF-CTFE) mixed matrix membranes were prepared by non-solvent induced phase separation method using self-made graphite carbon nitride nanosheet wrapped copper phosphide (CuxP@g-C3N4) as modification additive. The sequel of the incorporated CuxP@g-C3N4 nanosheet content on the morphology, pore structure and physicochemical structure of membranes was investigated in terms of pure water flux, anti-fouling and antibacterial properties. The results showed that the addition of CuxP@g-C3N4 nanosheets not only improved the hydrophilicity and mechanical property of the membranes, but also enabled PVDF-CTFE membrane with the ability of inactivation bacteria and self-cleaning, which significantly enhanced the anti-fouling performance of PVDF-CTFE membrane in complex environment. When the amount of CuxP@g-C3N4 reached 2 wt%, the mixed matrix membrane possessed outstanding comprehensive performance with the pure water flux of 641.1 L m(-2) h(-1), antibacterial rate over 99% and self-cleaning under simulated sunlight, making the mixed matrix membrane a potential choice for wastewater treatment. In conclusion, this study enlightened the fabrication strategy of multifunctional mixed matrix membranes.

Automated summary

In this study, antibacterial and self-cleaning mixed matrix membranes were prepared by incorporating copper phosphide-wrapped graphite carbon nitride nanosheets. The addition of these nanosheets improved the hydrophilicity and mechanical properties of the membranes, and also endowed them with the ability to inactivate bacteria and self-clean under sunlight. The mixed matrix membrane showed outstanding comprehensive performance for wastewater treatment.