Gold nanoparticles modified graphene foam with superhydrophobicity and superoleophilicity for oil-water separation.

Leakage accidents often occur during the production, transportation, and use of petroleum products, which is a common and serious environmental issue. It is of great significance and challenge to develop efficient materials for oil-water separation. This article introduces a simple and feasible method to prepare high-performance 3D graphene foam (GF) oil-absorbing material. Gold nanoparticles (Au NPs) are loaded on the surface of graphene foam by ion sputtering and then modified with 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT). The prepared graphene sponge is porous with a large specific surface area and excellent water repellency (water contact angle exceeding 150°). The superhydrophobicity of the materials is due to the interaction between the rough structure of gold nanoparticles and the reduction of surface energy by PFDT. These outstanding properties make the functionalized graphene foam have excellent oil absorption capacity, which can even be as high as 25.8 g/g, and it can still maintain high separation performance after 10 cycles of recycling. It is worth noting that the preparation of the material is simple and reusable. Therefore, the prepared graphene foam has the potential as a promising absorbent for oil spill purification.