Ultrahigh-flux and self-cleaning composite membrane based on BiOCl-PPy modified MXene nanosheets for contaminants removal from wastewater

Abstract

Membrane separation technology is considered as one of the most promising wastewater treatment technologies. However, difficulties in thorough water purification and poor fouling resistance in practical applications are some of the major concerns associated to membrane-based water purification. In the present investigation, a combination of efficient and environmentally friendly photocatalysis technology has been adopted for the fabrication of a series of BiOCl-PPy@MXene multifunctional photocatalytic composite membranes by stacking MXene nanosheets and BiOCl-PPy photocatalytic nanoparticles on polyethersulfone (PES) substrates. The composite membranes with BiOCl-PPy nanoparticles exhibited excellent permeation performance with pure water (flux of 3680.2 L m −2 h −1 ). Moreover, the composite membranes achieved 99.9% of combined removal rate for three different dyes and 96% for antibiotic (Tetracycline Hydrochloride) by physical sieving and photocatalytic degradation. The self-cleaning mechanism of composite membranes maintained good long-term permeability and selectivity during the cyclic tests. Hence, the service life of the membrane under visible light irradiation has been significantly improved without any compromise on the membrane performance. The density functional theory (DFT) calculation has been utilized to understand the mechanism in enhancing the photocatalytic activity of the composite membrane. • BiOCl-PPy@MXene composite membranes were fabricated via vacuum self-assembly. • The composite membrane displayed high flux and excellent photocatalytic activity. • The composite membrane exhibited self-cleaning and antibacterial properties. • DFT revealed the separation and degradation mechanism of composite membrane.