Chitosan/ZIF‐8 Composite Beads Fabricated by In Situ Growth of MOFs Crystals on Chitosan Beads for CO 2 Adsorption

Abstract CO 2 responsive polymer chitosan is introduced to fabricate polymer/MOFs composite materials used to explore CO 2 adsorption and recyclability. Chitosan beads (CBs) are successively immersed in the solution of Zn 2+ and the solution of 2‐methylimidazole to fabricate chitosan/ZIF‐8 composite beads (CBsZx) by in situ growth of ZIF‐8 crystal on chitosan beads. CBsZx are characterized by powder XRD, FT‐IR, SEM, TEM, TGA and BET. The morphology, size and distribution of the ZIF‐8 crystals on CBsZx are tuned by adjusting the concentration of Zn 2+ in the soaking solution. The coordination of the free amino groups on chitosan skeleton with Zn 2+ and self‐emulsifying properties of chitosan have played a key role in situ growth of the ZIF‐8 crystals on chitosan beads. Additionally, the adsorption capacity and recyclability of CBsZx for CO 2 has been evaluated. Compared with the pure ZIF‐8 crystals, the adsorption capacity of CBsZx for CO 2 is significantly enhanced by 90 %. The kinetic models indicate that the adsorption of CBsZx for CO 2 belongs to physical adsorption, when the ZIF‐8 crystals on chitosan beads have the regular shape and size. Moreover, the adsorption capacity of CBsZx for CO 2 is remained more than 80 % after 3 recycling.