Self-cleaning, antimicrobial, and antifouling membrane via integrating mesoporous graphitic carbon nitride into polyvinylidene fluoride

Mesoporous graphitic carbon nitride (MCN) photocatalyst was blended in polyvinylidene fluoride (PVDF) membrane through immersion-precipitation phase transformation. Various techniques were adopted to characterize the structure and morphology of MCN-PVDF hybrid membrane, which indicated that MCN was successfully integrated in PVDF. The MCN80-PVDF membrane exhibited enhanced hydrophilicity and antifouling properties. As the amount of MCN addition increased, the contact angle of membranes decreased from 68.33° to 57.12°, whereas the flux recovery rate increased by 28% as compared to the pristine PVDF. Meanwhile, MCN-PVDF membrane possessed photocatalytic, self-cleaning and antimicrobial activities. The MCN80-PVDF membrane was used to degrade cefotaxime (CFX) under sunlight irradiation. After five cycles of experiments, the degradation rate of CFX remained 97.4%. Additionally, MCN80-PVDF membrane achieved 3 log of E. coli inactivation under visible light irradiation for 4 h. The photogenerated h+ and reactive oxidative species were the primary reason for organics’ degradation and bacterial inactivation. In summary, the prepared hybrid MCN80-PVDF membrane with sunlight irradiation exhibited great potential for the treatment of real wastewater. •MCN was blended in PVDF via immersion-precipitation phase transformation.•MCN enhanced the permeability, hydrophilicity and antifouling of membrane.•The degradation of CFX under sunlight irradiation by MCN-PVDF achieved over 97%.•MCN-PVDF was stable and exhibited great antimicrobial and self-cleaning properties.