Ni/carbon aerogels derived from water induced self-assembly of Ni-MOF for adsorption and catalytic conversion of oily wastewater

Abstract

Herein, we reported a facile tactics for the fabrication of Ni nanoparticles embedded carbon (Ni/C) aerogels via water induced self-assembly of Ni-MOFs, and followed by pyrolysis carbonization under nitrogen atmosphere. The water induced assembly mechanism of Ni-MOF hydrogel was investigated by adjusting the ratio of water/ethanol and molecular dynamics simulation. Utilizing the nanofibers with hierarchical porous structures, the Ni/C aerogels with low density (27.9 mg/cm3), superhydrophobic (163.1° of water contact angle), high elasticity (8.94 MPa at 70% of strain) and large specific surface areas (144.6 m2/g) were fabricated, achieving remarkable adsorption efficiency (1903% to 3899%) and cycling stability (15 cycles) for various oil and organic compounds. After oil adsorption, the Ni/C500 aerogels can be recycled by using extra magnetic field owing to the magnetic properties of metal Ni nanoparticles (14.4 nm size). More importantly, the Ni/C500 aerogels can be used as a catalyst to further convert the adsorbed organic compounds into high value-added chemicals in the aqueous phase via catalytic hydrogenation reaction. Specifically, nitrobenzene was completely converted into aniline and selective hydrogenation of furfural transferred to tetrahydrofurfuryl alcohol was achieved. Therefore, the multifunctional Ni/C aerogels could be used to kill two birds with one stone for advanced treatment of oily wastewater.