Electrospun Cellulose Acetate–Polycaprolactone/Chitosan Core–Shell Nanofibers for the Removal of Cr(VI)

Core–shell-structured cellulose acetate–polycaprolactone/chitosan (CA–PCL/CS) nanofibers with excellent removal performance of hexavalent chromium (Cr(VI)) are developed by coaxial electrospinning. The effect of core-to-shell ratio on adsorption capability is studied. The results show that all core–shell-structured fibers possess higher adsorption capability and good durability in acidic environment compared with the CS powder adsorbent. CA–PCL/CS fibers with core-to-shell ratio of 0.442 have a maximum adsorption capability of 126 mg g −1 at room temperature. The adsorption kinetics reveals that chemisorption serves as the rate-determining step by notable electron transfer, share, or exchange between adsorbents and adsorbates. The adsorption equilibrium data of the core–shell-structured CA–PCL/CS fiber adsorbents are all well described by the Freundlich isotherm model, indicating the multilayer adsorption process. Herein, it is highlighted that the core–shell-structured CA–PCL/CS nanofibers have a promising prospect in removing Cr(VI) ions from waste water.