Synthesis and characterization of electrospun PAN-based activated carbon nanofibers reinforced with cellulose nanocrystals for adsorption of VOCs

Abstract

Electrospun Polyacrylonitrile/Cellulose nanocrystal (PAN-CNC) nanofibers with uniform diameter and smooth morphology were prepared. The nanofibers were stabilized, then activated to produce activated carbon nanofibers (ACnFs) and their physical and chemical properties were characterized. Last, the adsorption properties of ACnFs were tested for adsorption of methyl ethyl ketone (MEK) and cyclohexane. Scanning electron microscopy revealed that the addition of CNCs improves fiber uniformity and decreases fiber diameter due to enhanced electrical conductivity of electrospinning solutions. The addition of CNCs had minimal effect on fibers thermal stability; however, it brought large improvement in tensile strength. The pore size distribution indicated large volumes of micropores and mesopores in all samples. The maximum surface area and total pore volume were respectively 3497 m2/g and 2.62 cm3/g for 25%PAN-75%CNC nanofibers. The adsorption capacity for MEK and cyclohexane correlated well with the surface area of ACnF, reaching a maximum value of 1.7 and 1.8 gadsorbate/gadsorbent for MEK and cyclohexane, respectively. Compared to commercial activated carbons fiber and beads, the prepared ACnF exhibited higher capacities and faster adsorption kinetics due to larger surface area, higher mesoporosity, and better mass transfer. These results indicate that using CNC improves the mechanical and adsorption properties of electrospun PAN nanofibers. This article, for the first time, puts forward CNC reinforced activated carbon nanofibers as suitable adsorbents for environmental remediation applications.