Superhydrophobic magnetic reduced graphene oxide-decorated foam for efficient and repeatable oil-water separation

Fabrication of robust and cost-effective adsorbents for quick and easy clean-up of oil spills is highly desired. Here, we developed one novel porous melamine foam (MF) with both the reduced graphene oxide (rGO) and hydrophobic magnetic nanoparticles decorated on its skeleton (r-MGMF) via a stepwise assembly and reductive annealing process. The resultant r-MGMF shows highly superhydrophobic with a water contact angle (WCA) of 164.4 ± 2.0°, and superparamagnetic with a saturated moment of 10.59 emu/g. With its porous structure, superhydrophobic surface and magnetic property, r-MGMF can move under the control of a magnet, and is highly efficient to separate oil from water with a high adsorption capacity, and for example, can adsorb canola oil about 54.13 times of its own weight. The used r-MGMF can be regenerated by a simple squeezing process without significant structure and efficiency degradation at least ten runs of adsorption-regeneration process. Additionally, the r-MGMF is competent to continuously separate an oil-water mixed flow with a separation efficiency of above 96.33%. High selectivity, hydrophobic stability, large adsorption capacity, and excellent recyclability promise r-MGMF a great potential in oily wastewater treatment.