Design of stable super-hydrophobic/super-oleophilic 3D carbon fiber felt decorated with Fe3O4 nanoparticles: Facial strategy, magnetic drive and continuous oil/water separation in harsh environments

Stable and efficient separation of oil slicks from oil-contaminated water in harsh environments is still a big challenge. Recently, three-dimensional hydrophobic/super-oleophilic materials exhibit promising application in continuous oil/water separation. Herein, we developed a facial method to prepare three-dimensional super-hydrophobic/super-oleophilic carbon fiber felt (CFF) materials by anchoring the hydrophobic Fe3O4 nanoparticles onto 3D CFF. Owing to the well-defined micro-/nano-structure and low surface energy, as-obtained CFF materials showed high water contact angle of 164.1 ± 1.3° and low oil contact angle of 0°. As a result, as-prepared CFF materials exhibited excellent adsorption driven by external magnetic field and continuous oils separation from immiscible oil/water mixtures, with the high separation efficiency up to 99.99%. More importantly, the resulting super-wetting material showed stable super-hydrophobic property and continuous oil/water separation performance in harsh environments such as strong corrosive/salt solutions, organic solvents, and high/low-temperature systems. Therefore, this work provides an alternative strategy to obtain 3D super-hydrophobic/super-oleophilic materials with easy operation, durable and efficient continuous oil/water separation performance, exhibiting potential application for treating the large-scale industrial oily wastewater in harsh environments.