A tunable amphiphilic Enteromorpha-modified graphene aerogel for oil/water separation

Highlights: • The Enteromorpha modified graphene aerogel (EGA) was fabricated via hydrothermal-freeze casting treatment. • The interfacial wettability of EGAs can be controlled by changing Enteromorpha doping and the freezing temperature. • The Enteromorpha prevents graphene from stacking and give graphene aerogels compressibility. • The EGA can collect oil or water selectively by pre-wetted for oil/water separation. Three-dimensional graphene aerogel materials used for treatment of oily wastewater with sophisticated composition remains a challenge due to volume shrinkage, resulting in single-function and low adsorption capacity. In this work, renewable Enteromorpha was introduced into the graphene aerogel via facile hydrothermal-freeze casting treatment, forming the compression, ultralight and amphiphilic adsorbent for oil spill cleanup and water pollution remediation. Meanwhile, further freeze casting avoids aerogel collapse for capillary tension during drying and produce more hierarchical pores. As for oil spill clean up, the Enteromorpha modified graphene aerogel (EGA) exhibits excellent adsorption capacity towards oil and organic solvents than pristine graphene aerogel (GA). Even after several cycles by compression and heat treatment, it still has a stable adsorption capacity for oil and organic solvents. The EGA also showed high ability to absorb water-soluble pollutants, such as dyes through hydrogen bonding and electrostatic reactions between dye molecules and aerogel. The facile strategy to fabricate the Enteromorpha-based amphiphilic EGA broadens the applications in water treatment through the high-value utilization of Enteromorpha.