Coordination-driven in-situ self-assembled prussian blue/alginate hydrogels composite mesh with underwater superoleophobicity for oil/water separation and self-cleaning performance

The treatment of oily wastewater has become an urgent problem. In the process of water treatment, the superhydrophilic and underwater superoleophobic filter meshes offer attractive advantages because of the efficient separation efficiency and easy industrialization. Here, a stable superhydrophilic and underwater superoleophobic Fe composite mesh coated by Prussian blue/alginate hydrogels (PB/[email protected] composite mesh) was successfully prepared via coordination-driven in-situ self-assembly. PB/[email protected] composite mesh combined the advanced oxidation processes (AOPs) activity of PB with the hydrophilic property of alginate hydrogels (AHs). This composite mesh exhibited the exceptional self-cleaning performance through the activation of peroxymonosulfate (PMS) and H2O2. In this self-cleaning process, the concentration of metal ions was reduced by 82% owing to the strong cross-linking effect between AHs and metal ions for decreasing the secondary pollutions. Simultaneously, PB/[email protected] composite mesh showed a good underwater oil contact angle (OCA>156°). And the composite mesh demonstrated outstanding oil/water separation performances, such as 99.5% of separation efficiency and 180,000–280,000 L m−2 h−1 of water flux. Besides, PB/[email protected] composite mesh exhibited outstanding stability, durable alkaline resistance, and salt resistance in oil/water separation process, which made it a potential material for the application of oil/water separation and self-cleaning performance.