Reduced graphene oxide modified melamine formaldehyde (rGO@MF) superhydrophobic sponge for efficient oil-water separation

The present work describes the fabrication of superhydrophobic and superoleophilic reduced graphene oxide coated melamine formaldehyde (rGO@MF) based sponge for efficient removal of oils and organic solvents from oil-water mixture. The rGO@MF sponge was synthesized using commercially available melamine sponge, GO solution, and hydrazine hydrate by hydrothermal treatment. Phase and microstructural analysis show that as-synthesized rGO@MF possesses ultrathin coating of rGO sheets onto porous MF sponge. Moreover, as-prepared rGO@MF sponge exhibited contact angle (CA) similar to 162 degrees and 0 degrees on a sessile water and oil droplet, respectively. Oil water separation test shows that rGO@MF sponge can remove similar to 90-120 times oils by its weight. Moreover, repeated sorption-mechanical squeezing test of oil-water mixture sheds light that rGO@MF sponge is fully reusable and similar to 40-50% oil can be recovered after 10 cycles.