Super-hydrophobic graphene-based high elastic sponge with superior photothermal effect for efficient cleaning of oil contamination

Oil spills are frequent and often accompanied by chemically corrosive and complex operating environments, so there is an urgent need for new absorbent materials that can absorb oil efficiently and with stable performance. Herein, we reported a reduced graphene oxide coated melamine sponge (F-rGO@MF) modified by silane grafting, which had excellent superhydrophobic/superoleophilic surface properties (WCA up to 157.7°), high absorption capacity (58.7–147.8 g/g) for a variety of oils, and could perform multiple absorption cycles. The separation efficiency of the oil/water mixture was as high as 99.32%, and the separation efficiency could still reach 97.48% after 80 separation cycles. The absorbent could also separate oil and water continuously by peristaltic pump. Besides, F-rGO@MF still retained floating and chemical stability under strong corrosive environment. More importantly, due to the photothermal property of rGO, the surface temperature of F-rGO@MF could rapidly rise to 101 °C under 1.0 kw/m2 light intensity for 225 s, which was contribute to the viscosity reduction of crude oil and absorbed 14.75 g of crude oil in 7 min, providing the possibility of absorbing high viscosity oil spills.