Super‐Wetting Porous g‐C3N4 Nanosheets Coated PVDF Membrane for Emulsified Oil/Water Separation and Aqueous Organic Pollutant Elimination

Abstract

AbstractSuper‐wetting multifunctional membranes are highly attractive in the current decade in the environmental remediation of wastewater containing water‐insoluble emulsified oils and water‐soluble hazardous organic pollutants. Herein, hydroxyl modified porous g‐C3N4 nanosheets (CNNS) coated polyvinylidene fluoride (PVDF) membrane is fabricated by a facile vacuum pumping process. Hydroxyl modified porous g‐C3N4 nanosheets are firmly immobilized on flexible PVDF substrate via sodium alginate (SA) adhesive to create a stable surface micro/nanohierarchical structure. The fabricated CNNS/SA/PVDF membrane achieves the desired surface wettability of superhydrophilicity/underwater superoleophobicity with an anti‐oil‐fouling property. The functionalized membrane exhibits above 99% emulsified oil rejection rate with excellent stability and recyclability when separating oil‐in‐water emulsions. Besides, visible‐light‐response CNNS endow the as‐prepared membrane with excellent photocatalytic activity. The resulted CNNS/SA/PVDF membrane can eliminate organic dye both in static and dynamic water with high flux recovery ratio and renewability, which conducted the procedures of photodegradation of organic dye adsorbed on the membrane surface after filtering the contaminative flowing aqueous solution, and directly the photodegradation of organic dye in stationary aqueous solution, respectively. This facile‐fabrication and high‐performance CNNS/SA/PVDF membrane provides a promising practical application toward oily and organic wastewater treatment. It also promotes the utilization of surface wettability modified g‐C3N4 nanomaterial in the construction of multifunctional interface membrane for environmental purification.