Highly hydrophobic and ultralight graphene aerogel as high efficiency oil absorbent material

In this paper, we reported the preparation of a new type of highly hydrophobic and ultralight 3D porous graphene aerogel (GA) with graphene oxide as precursor and melamine formaldehyde (MF) microspheres as spacer and pore forming agent, followed by hydrothermal reduction, freeze-drying and calcination process. The resultant calcined MF-GA (cMF-GA) integrates a collection of unique properties including high porosity (up to 99.7%), large specific surface area (317 m²/g), low density (5 mg/cm³) and high hydrophobicity (contact angle 141°), and therefore shows excellent absorption capacity to the organic solvent and oils. The results indicate that cMF-GA exhibits fast absorption rate within 20 s and maximum sorption capacities up to 220 g/g for acetone, cyclohexane and toluene, 270 g/g for phenixin, and 230 g/g for diesel oil, which are superior to previously reported carbon-based superabsorbents. Moreover, the proposed cMF-GA absorbent shows good recyclability and its recovery maintains at 91% after 10 cycles. These characteristics demonstrate the great promise of cMF-GA as a highly efficient and low-cost absorbent in practice application of removing large-scale oil or toxic organic spills.