A flexible and free-standing multifunctional membrane for high-efficiency wastewater purification and oil/water separation with superhigh flux and ultralow fouling

Abstract

The development of membrane techniques provides a new and effective choice to alleviate the crisis of clean water scarcity. Low water flux and membrane fouling are two major challenges during wastewater purification and oil/water separation processes, which restrict the wide applications of the commercial membranes. Herein, we reported a free-standing and flexible carbon nanofiber (CNF)/In2S3 multifunctional membrane, which was delicately designed and fabricated by growing visible light responsive In2S3 flower-like nanostructures on the electrospun CNF membrane matrix. This novel multifunctional membrane possessed the combined advantages of excellent mechanical flexibility, superhigh water flux, ultralow membrane fouling and high oil rejection rates, due to its merits with outstanding properties including (1) the robust CNF membrane matrix, (2) interconnected three-dimensional (3D) scaffold-like structure, (3) excellent photodegradation activity, and (4) the superhydrophilic and superwetting property. In addition, this innovative CNF/In2S3 membrane can separate both immiscible oil/water mixtures and oil-in-water emulsions with extremely high efficiency (>99%). Hence, this work provides a novel technique for reasonable fabrication of composite membranes with outstanding wastewater purification and oil/water separation efficiency, and indicates this novel CNF/In2S3 multifunctional membrane has bright future in membrane industry.