Ultralight, superhydrophobic and fire-resistant nitrogen-doped graphene aerogel for oil/water separation

The simultaneous achievement of graphene aerogels with low density, high adsorption capacity and selectivity, as well as high mechanical strength, holds great significance but remains a challenging task. By adjusting the concentration and ratio of graphene oxide, dopamine and L-ascorbic acid, the hydrogel without obvious volume shrinkage and stability was synthesized by hydrothermal reaction at low temperature, after freeze-drying and calcination, nitrogen doped graphene aerogel (NGA) with ultralight, superhydrophobic, superoleophilic, fireresistant, and compressible/recoverable were obtained. The density of NGA is only about 1.9 mg/cm3, and the water and oil contact angles in air are 153.3 degrees and 0 degrees, respectively. Given the aforementioned beneficial features, NGA can efficiently select and adsorb multifarious of oils and organic solvents in oil/water mixtures so as to achieve oil/water separation. Remarkably, NGA exhibits an impressive adsorption capacity of up to 150-305 times its own weight, and it also possesses excellent adsorption recyclability. Therefore, NGA has great potential in the treatment of oil pollution in the water environment.