MIL-101(Fe) Networks Supported on Fluorinated Graphene Nanosheets as Coatings for Oil Sorption
Yogapriya Ravi, Iniya Prasanthi, Swarnamayee Behera, K. K. R. Datta
Abstract
Oil spill leakage and industrial oily wastewater discharge into water bodies cause a considerable threat to the marine network and human health. Selective oil/organic solvent collection devices with effectual recovery of the oils from the water surface have been studied through engineering advanced materials displaying a special wetting property. Herein, we develop a water-repellent MIL-101(Fe) material supported over fluorinated graphene (FG) nanosheets by in situ synthesis under ambient conditions. FG nanosheets not only provide the necessary structural nodes for the growth of octahedral MIL-101(Fe) nanostructures but also bring in the necessary hydrophobicity with a water contact angle of 146 ± 1°, possessing a surface free energy of 12.7 mJ m–2. Powdered FG-MIL-101(Fe) demonstrated differential wettability with extreme chemical stabilities toward acidic and basic water. The solution processability of FG-MIL-101(Fe) was amalgamated with a copper mesh and a polydimethylsiloxane sponge via spray coating and inoculation methods en route designing oil recovery prototypes. The submersible FG-MIL-101(Fe)-PDMS sponges displayed selective pickup of oil and organic solvents with the sorption ranging from 1.85 to 3.8 g/g, in addition to displaying recyclability up to 10 cycles along with physical and chemical robustness. Additionally, the FG-MIL-101(Fe)-PDMS macroporous sponge was subjected to demulsification of a toluene/water system taking the distinct toluene pickup property. Selective oil recovery containers were fabricated by directing FG-MIL-101(Fe) suspensions on a copper mesh resulting in oil-collecting devices. Organics/oils selectively infiltrated into the FG-MIL-101(Fe)-coated copper mesh superwetting containers with separation efficiencies in the range of 96–100%. The translation of FG-MIL-101(Fe)-modified substrates was utilized to tackle real-time oil/organic collection prototypes from oil–seawater mixtures under turbulent conditions demonstrating excellent sorption abilities ranging from 4.4 to 5.6 g/g (by superwetting sponges) along with super efficiencies in the range of 92–98% (via superwetting containers).