Bioinspired copper-graphene oxide hybrid membrane prepared via electrochemical-driven strategy: design, mechanism, and oil-water separation

[Display omitted] •Cu-GO hybrid membrane was fabricated by a facile electrochemical-driven strategy.•Cu-GO hybrids possess bioinspired lanceolate microstructure on the membrane surface.•The membrane can efficiently separate oil–water mixtures/emulsions driven by gravity.•The membrane can keep fouling-resistant and stable under harsh conditions. Constrained by intricate manufacturing processes, poor flux, and unsatisfied durability, a handy strategy to produce hybrid membranes with superior properties in oil–water separation was highly desired. Herein, a novel electrochemical-driven method was developed to realize graphene oxide (GO) production and simultaneously self-growth of Cu-GO hybrids on stainless-steel mesh to obtain the desired lanceolate Cu-GO microstructure. After optimization, the microstructure endowed the resultant Cu-GO hybrid membrane (Cu-GO HM) with underwater superoleophobicity (165.8° for kerosene), superior anti-oil-fouling performance, and excellent stability under harsh conditions (e.g., saturated NaCl, acidic, alkaline solutions, and various organic solvents). Noteworthily, Cu-GO HM can achieve around 99.5% separation efficiency and a superior flux of 182160 L m-2h−1 for oil/water mixtures solely driven by gravity. Additionally, the membrane can effectively separate oil-in-water emulsions. Even after suffering from multi-cycle sandpaper sanding and high-frequency ultrasonic damage, lanceolate Cu-GO microstructure still showed strong cohesion, guaranteeing the mechanical stability and durability of Cu-GO HM. The membrane also showed brilliant reusability through 50 cycles and long-term separation tests. Furthermore, the mechanism of the preparation and separation process was discussed in detail. The distinctive advantages of Cu-GO HM synthesized by electrochemical driven can ensure an available strategy for efficient oil–water separation.