One-step synthesis of peanut hull/graphene aerogel for highly efficient oil-water separation

Abstract

Peanut hull has been used to prepared three-dimensional self-assembled peanut hull/graphene aerogels (3D-PG) in a very simple, green and low-cost way, successfully making use of agricultural waste as well as achieving base-induced one-step synthesis of 3D-PG for oil-water separation. The addition of peanut hull has increasingly improved the properties of graphene aerogels. A 9.6 mg 3D-PG can support a 200 g counterpoise, more than 2000 times its own weight. Meanwhile, the surface of aerogel has outstanding hydrophobicity and oleophilicity due to the addition of peanut hull in the graphene oxide (GO) aqueous dispersion, with the water and oil contact angles of 141° and 0°, respectively. This endows the 3D-PGs outstanding absorbing capability with the quality factor Q from 3214% up to 7933% for organic solvents and oils. Noteworthily, the adsorption equilibrium can be achieved within 1 min. In addition, the dynamic test indicated highly efficient oil-water separation of 3D-PG. Results also showed 3D-PG with super low density, large specific surface area, excellent adsorption capacities and superior adsorption recyclability (93%). Such outstanding oleophilic properties make the agricultural waste make the 3D-PG tremendously potential applications for oil absorbing, recovery and oil-water separation.