Graphene/MOF-based composite materials in three-dimensional (3D) architectures are promising for the treatment of oil-containing wastewater by absorption owing to their intrinsic properties of graphene and metal-organic frameworks (MOFs), such as high porosity, ultralow density, and facilely tailored superwettability. In this study, novel wrinkled 3D microspherical MOF@rGO composites with both superhydrophobic and superoleophilic properties were developed by embedding MOF nanoparticles between graphene oxide (GO) nanosheets, followed by high-temperature reduction self-assembly. The microspherical composites feature a unique micro/nano hierarchy consisting of crumpled reduced GO (rGO) nanosheets intercalated with well-dispersed MOF nanoparticles. Combined with the superwettability and abundant meso/microporosity, the peculiar architectures of wrinkled ZIF-8@rGO microspheres show very fast absorption rates and high sorption selectivity for organic solvents and oils from water.
Keywords: graphene-based microspheres; metal-organic frameworks; oil-water separation; superhydrophobicity; superoleophilicity.
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