Three-Dimensionally Macroporous Fe/C Nanocomposites As Highly Selective Oil-Absorption Materials

Abstract

In this study, three-dimensionally macroporous Fe/C nanocomposites were investigated as highly selective absorption materials for removing oils from water surface. The macroporous nanocomposites were synthesized by sintering a mixture of closely packed polystyrene microspheres and ferric nitrate precursor. These nanocomposites exhibited superhydrophobic and superoleophilic properties without the modification of low-surface-energy chemicals. And the pore size of the nanocomposites, which is crucial for the oil-absorption capacity, was tuned by varying the diameter of polystyrene microspheres. The macroporous nanocomposites fast and selectively absorbed a wide range of oils and hydrophobic organic solvents on water surface, and the removal of the absorbed oils from the water surface was readily achieved under a magnetic field. Moreover, the nanocomposites still kept highly hydrophobic and oleophilic characteristics after repeatedly removing oils from water surface for many cycles. Because of frequently occurring environmental pollution arising from oil spills and chemicals leakage, the results of this study might offer a kind of efficient and selective absorbent materials for removing oils and nonpolar organic solvents from the surface of water.

3D Self‐Supporting Porous Magnetic Assemblies for Water Remediation and Beyond

“…In this way, 3D-SPMAs could be easily guided towards the polluted region so as to adsorb floating oil spills. Actually, almost all works about hydrophobic 3D-SPMAs have demonstrated this feature, [4,33,[39][40][41]92,97,106,112] such as CNTs sponges, MWNTs/PDMS nanocomposites, and polyurethane/iron oxide foams (Figure 13a-c). However, it should be noted this magnetic-driven adsorption process only accounts for the treatment of on-water oil spills.…”

“…[35,38,41,58,59,[91][92][93] For example, Brown et al prepared low-density Fe 2 ZnO 4 aerogels (≈12-15 mg cm -3 ) by epoxide-induced co-precipitation of ferric nitrate and zinc nitrate followed by supercritical drying. [58] For some metal salts with low solubility, templating can be an alternative choice.…”

“…Several materials, including modified PU sponges and Fe/C nanocomposites have been demonstrated to show this ability (Figure 13d,e). [41,92,106,112] Whereas, it could be foreseen that the 3D-SPMAs can only be collected by the magnetic when they adsorb a small amount of oil. If a large quantity of oil was adsorbed, the 3D-SPMAs would undergo several tens or even several hundred times weight gain.…”

Versatile fabrication of magnetic carbon fiber aerogel applied for bidirectional oil–water separation

“…8a, the magnetic superhydrophobic CF aerogels exhibited absorption capacities ranging from 29 to 70 times their weight for above oils and organic solvents. The sorption capacities are superior to many previously reported sorbents [17,[27][28][29], such as PDMS sponges (4.7-20 times) [17], graphene/a-FeOOH composites (10-30 times) [27], 3D macroporous Fe/C (4-10 times) [29]. Furthermore, repeated recycle tests were performed for its essential in oil/chemical cleanup.…”

Templated Synthesis for Nanoarchitectured Porous Materials

“…For examples, Pan et al investigated a magnetic macroporous Fe/C nanocomposite to separate oils from the water surface. 262 The ability of macropores to remove oil were compared according to their average diameters and the results indicated that larger pores led to a better removal efficiency. In addition, macroporous carbon-based functional magnets can easily collect pollutants from oil and thus, are promising recycling absorbents.…”