Biomimetic strategy for fabrication of bifunctional graphene oxide-biomaterial aerogel as highly porous antifouling material for oil/water separation

Abstract

Fabrication of Janus type asymmetric wettable aerogel with high mechanical strength and antifouling property remains a great challenge for effective oil/water separation. Herein, inspired by the lotus leaf structure, we reported eco-benign fabrication of stearic acid coated biomaterial functionalized porous network structure of graphene oxide (GCCS) nanobioaerogel with Janus wettability (water contact angle: 129.4 ± 10.1° at top side and 40.35 ± 2.4° at bottom side), excellent modulus of elasticity (4.74 kPa), and antibiofouling properties. FTIR results revealed that the covalent, electrostatic, hydrophobic, and π-π interactions of graphene oxide (GO) and biomaterials provided high mechanical strength to the GCCS nanobioaerogel. The bifunctional GCCS nanobioaerogel with 50% hydrophobic coating exhibited excellent water floating and anti-overturning behaviour under high waves. Moreover, this asymmetric aerogel simultaneously removed oil through top side and water soluble dyes through bottom of the aerogel at the oil/water interface. The bifunctional GCCS nanobioaerogel exhibited high oil removal capacity and removed 227.53 ± 9.35 g/g of oil due to high surface area and porous structure. At the same time dye adsorption capacity of the GCCS nanobioaerogel was calculated as 204.17 ± 7.49 mg/g at optimum pH = 4.0, 60 °C in both single and multi-component system. In addition, the nanobioaerogel exhibited excellent bactericidal activity (99.999%) along with antibiofouling property and effectively disinfect the bacteria contaminated water. Moreover, the dyes and oils were easily eluted from GCCS nanobioaerogel and recycled multiple times. Thus, this manuscript highlights the potential use of renewable natural biomaterial to fabricate biomimetic porous aerogel material with asymmetric wettability, high mechanical strength and antifouling properties for efficient removal of oil, dyes and microbial pathogens.