Multifunctional graphene/poly(vinyl alcohol) aerogels: In situ hydrothermal preparation and applications in broad-spectrum adsorption for dyes and oils

Comprehensive treatment of multifarious contaminations in waterbody demands multifunctional adsorbents with easy reusability, high efficiency, and broad-spectrum adsorption performance. Herein hydrothermally reduced graphene oxide/poly (vinyl alcohol) (TRGO/PVA) aerogels fulfilling these requirements were developed via a facile and green in situ hydrothermal reduction followed by direct sol-aerogel transformation strategy. The interfacial interaction between TRGO sheets and PVA macromolecules as proved by various methods could effectively prevent TRGO from aggregation, which improves mechanical and adsorption performances and assures reusability of aerogels. The aerogels demonstrate an attractive broad-spectrum universality in adsorbing diverse cationic, anionic and nonionic dyes, surpassing most adsorbents that could only remove either positively or negatively charged dyes. The aerogels demonstrate a promising synergetic effect for adsorption two oppositely charged dyes, exhibiting the highest total adsorption amount (>900 mg/g) among known absorbents for removing mixed dyes. Besides, the aerogels after hydrophobic modification are able to effectively adsorb common oils and organic solvents spilling on water. Furthermore, the aerogels are compressible, dimension stable and solvent resistive and can be easily regenerated, bringing a great superiority in the comprehensive treatment of multiple contaminations in waterbody.

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