Hierarchically porous N-doped carbon nanofibers derived from ZIF-8/PAN composites for benzene adsorption

Coupling with electrospinning technique, metal–organic-frameworks (MOFs)-derived porous carbon fibers exhibit a great potential application in the adsorption of volatile organic compounds (VOCs) because of their huge surface area, high porosity, as well as sufficient heteroatom-doped active sites. In this work, the hierarchically porous N-doped carbon nanofibers are obtained after the pyrolysis of zeolite imidazole framework-8 and polyacrylonitrile (ZIF-8/PAN) composite fibers synthesized by electrospinning method. The N-doped carbon nanofibers fabricated in N₂ atmosphere (N-CF-N₂) present an enhanced adsorption capacity of 694 mg/g for benzene because of the synergistic effect of the hierarchically porous structure and the abundant N-species-containing active sites. It is also interesting that the N-doped hierarchical carbon nanofibers fabricated in Ar atmosphere (N-CF-Ar) exhibit a low benzene adsorption as compared with the N-CF-N₂, which can be attributed to the porous structure damage caused by the bombardment of heavy Ar atoms on the pore shells during the pyrolysis. These results not only show a promising application of the as-fabricated N-CF-N₂ in adsorption of VOCs for air purification due to its merit of cost-efficient, large-scale production, and excellent adsorption capacity, but also expand the potential of electrospinning technology and composite fibers in volatile organic gas adsorption.