Durable and super-hydrophilic/underwater super-oleophobic two-dimensional MXene composite lamellar membrane with photocatalytic self-cleaning property for efficient oil/water separation in harsh environments

Super-wetting membranes with outstanding permeation and anti-fouling performance are promising candidates for highly-efficient oily wastewater treatment. Herein, we designed a facile strategy to fabricate the superhydrophilic/underwater super-oleophobic two-dimensional MXene-based composite membrane via vacuum assisted self-assembly of two-dimensional MXene nanosheets on porous polyvinylidene fluoride (PVDF) substrate and in situ mineralization of photocatalyst beta-FeOOH on the membrane surface. Benefiting from the inherent super-wettability and regulated lamellar structure (Short transport pathway and abundant nano channels), the resultant MXene-based composite membrane displayed fast permeation flux (500.38-1022.7 L m(-2) h(-1)) and favorable separation efficiency (99.32-99.72%) for a series of micro-scaled oil-in-water emulsions. Importantly, the excellent photo-induced self-cleaning capability and low oil-adhesion contributed to the high anti-fouling resistance, outstanding reusability, and durability of 2D MXene composite membrane. Moreover, the 2D MXene composite membrane exhibited superior chemical stability, which enabled it to maintain highly efficient oil/water separation performance in high-temperature, high salty, and strongly corrosive conditions. This work provides a feasible route to fabricate durable super-wetting 2D membranes with photo-Fenton selfcleaning capability for the oily wastewater treatment in harsh environments.

Automated summary

This study presents a facile strategy to fabricate a two-dimensional MXene-based composite membrane with excellent permeation flux and separation efficiency, along with outstanding anti-fouling resistance and durability, even in harsh conditions, maintaining highly efficient oil/water separation performance.