One-Step Solution-Immersion Process of Hydrophobic Octyl Graphene Oxide-Modified Nickel Foam for Highly Efficient Oil-Water Separation.

Abstract

Hydrophobic foam was prepared by immersing nickel foam in a dispersion of octyl group-grafted graphene oxide (GO) and used to clean up oil–water mixtures. Octyl graphene oxide (C8-GO) was synthesized using GO and triethoxyoctylsilane by a solvothermal method. The resulting coverage of the foam was characterized, and the surface morphology of the foam was also investigated. The static water contact angle (SWCA) was measured to evaluate the change in wettability of the developed foam. The pristine smooth microstructure of the nickel foam became rough after being covered with the C8-GO nanosheets. The SWCA of C8-GO nickel foam (C8-GO NF) surface was approximately 147°. The C8-GO NF can float on the surface of the water in contrast to the easy-sinking unmodified foam, demonstrating good hydrophobicity. Furthermore, the C8-GO NF showed outstanding performance in organic compound adsorption and excellent efficiency in oil–water separation. The reusability and durability of the obtained foam are evaluated to highlight its usability in more complicated scenarios. The use of C8-GO NF was proved to be a promising strategy for oil–water separation under harsh circumstance.