Vapor–Liquid Deposition Strategy To Prepare Superhydrophobic and Superoleophilic Graphene Aerogel for Oil–Water Separation

The problems of high
temperature and volume shrinkage are frequently
encountered in the process of fabricating superhydrophobic graphene
aerogels. We present ultralight graphene aerogels with superhydrophobicity
and superoleophilicity by a vapor–liquid deposition process.
The graphene aerogels are prepared by graphene oxide assembled into
monolithic graphene hydrogel in dopamine-mediated aqueous solution
at mild temperature and a sealed reaction, then by directional freezing
and freeze-drying. Subsequent fluorinated alkyl silane is introduced
to produce ultralight graphene aerogel by vapor–liquid deposition
treatments; the surface of the aerogel has outstanding superhydrophobicity
and superoleophilicity with water and oil contact angles of 160.2°
and 0°, respectively. In addition, the resulting graphene aerogels
showed super low density, large specific surface area, excellent adsorption
capacities, and superior adsorption recyclability. Its adsorption
capacity was higher than 109 g/g for the used common oils and organic
solvents. Its properties suggest applications in the field of oil
adsorption and oil–water separation. The new strategy may open
up a new way to design high-performance superhydrophobic 3D graphene
monoliths for water treatment.