Graphene-based macromolecular assemblies as high-performance absorbents for oil and chemical spills response and cleanup

Oil and chemical spills inflict serious detrimental impacts on the environment, the extent of which often exceed the domains of general flora and fauna. In order to tackle recurrent oil/chemical spillage events, the design and development of highly porous and lightweight absorbents, possessing both hydrophobic and oleophilic characteristics, have gained considerable momentum over the last several years. Particularly attractive for a fast and an efficient removal of high-viscosity fluids from water are three-dimensional (3D) graphene-based macromolecular assemblies (GMAs), conceptualized based on integration of 2D graphene and graphene oxide nanosheets in the form of aerogels, foams, beads, and porous films. This can be credited to their outstanding physicochemical characteristics and superlative mechanical features, including inherent hydrophobicity, enhanced oleophilicity, precise and physically linked permeable networks, enormous surface area, and profound porosity, amongst others. Herein, we provide a systematic overview of the contemporary progress towards the fabrication of innovative 3D GMAs for eliminating oils and organic solvents from water surfaces, predominantly from the viewpoint of molecular design and engineering. Further, we highlight the various surface modification strategies that can be exploited to extend the absorption capacity of bulk hydrocarbons by 3D GMAs. Additionally, underlying challenges are identified and original future research plans are proposed, toward strategizing further advances in this promising environmental restoration approach.