A facile strategy toward hydrophobic–oleophilic 3D Fe foam for efficient oil–water separation

In this work, we present a hydrophobic–oleophilic Fe foam for oil–water separation. Hydrophobic–oleophilic Fe foam was fabricated simply through dip-coating with n -dodecyl mercaptan. The morphology, chemical composition and water contact angle of the Fe foam were characterized. The Fe foam could absorb a variety of oils, such as diesel, toluene, xylene, cyclohexane, dodecyl methacrylate, crude oil, 1,2-dichloroethane, hexane and chloroform, these oils could be underwater or on water surface, and it exhibited excellent durability, verified by the high separation efficiency (more than 98.8% for a cyclohexane–water mixture) after reusing for 48 times. Furthermore, oil collection with the Fe foam could be controlled remotely using external magnetic field, and the Fe foam displayed high flux, good anti-corrosion and wear resistance. The simple and low-cost fabrication method enabled the Fe foam to be a promising candidate for large-scale oil–water separation and for remotely controllable water purification.