Construction the soil-root-like heterostructure of Fe(Ⅲ)-MOF/AgNWs composite membrane with photo-Fenton antifouling performance towards complex wastewater remediation

Abstract

Developing a novel type of high-performance catalytic separation membrane with multifunctional remediation towards efficiently complex wastewater has been an anticipated goal. Inspired by the natural soil filtration system, we successfully constructed a soil-root-like Fe(Ⅲ)-MOF/AgNWs heterostructured membrane (AgNWs/CMC@NMB) with photo-fenton degradation property through a facile self-assembly approach under vacuum. Herein, sodium carboxymethyl cellulose(CMC) and silver nanowires (AgNWs) acted as the root, which were boned with the soil-like of the nubbly NH2-MIL-88B(Fe) aggregation by electrostatic force and hydrogen bonding interaction to form a stable soil-like heterostructured membrane. The resultant AgNWs/CMC@NMB membrane revealed remarkable selective wettability (water contact angles (WCAs) ∼0°, underwater oil contact angles (UWOCAs) > 155°), and exhibited splendid removal efficiency (>99 %) for insoluble oils under separation flux of 1343 L m−2 h−1 bar−1. Profiting from a soil-root-like porous filter structure, AgNWs/CMC@NMB membrane achieved concurrent treatment of the insoluble oils and soluble dyes by one-step efficient filtration, notably, the disposal efficiency for anionic and cationic dyes by soil-root-like structure reached above 96.7 %. Moreover, acting like roots in the soil to transport water and stabilize the soil, AgNWs facilitated electron transfer of the photo-Fenton system of Fe-MOF and enhanced the photocatalytic degradation capacity of composite membrane for the organic contaminant, which also endowed the photo-induced regeneration of fouled membrane. Overall, the construction of Fe(Ⅲ)-MOF/AgNWs composite membrane with a Soil-Root-like heterostructure emerged as a feasible route to achieve the complex sewage remediation.