Nonfluorinated, mechanically stable, and durable superhydrophobic 3D foam iron for high efficient oil/water continuous separation

Abstract The frequent oil spills and the discharge of oily wastewater have a severe impact on the sustainability of the environment and the ecosystem, which make an urgent need to develop a low-cost, mechanically stable, non-toxic, eco-friendly, corrosion-resistant, and highly efficient oil/water separation materials. Hence, a 3D superhydrophobic foam iron (SHFI) was prepared for oil/water continuous separation, zinc–iron (ZI) coating being electrodeposited on the 3D foam iron (FI) in an alkaline cyanide-free glycerol electrolytic bath, followed by the modification of tetradecanoic acid. Besides superhydrophobicity (Water contact angle: 158° and Sliding angle: 2°), the SHFI was provided with good anti-corrosion, excellent chemical stability, and outstanding mechanical stability against 100 cycles of abrasive paper (800 grit) abrasion at 5 kPa. Furthermore, the SHFI is able to achieve high efficiency of oil/water separation up to 99.3%. More importantly, the 3D SHFI can be designed into a device for oil/water continuous separation. The whole process of the preparation of SHFI is facile, green, and economic. Predictably, the 3D SHFI and the designed device will be promising for the actual oil/water continuous separation.