Abstract
A novel citrate-crosslinked Zn-MOF/chitosan (ZnBDC/CSC) composite was successfully prepared by immobilizing Zn-MOF (ZnBDC) on citrate-crosslinked chitosan (CSC) using citric acid as a chemical bridge. ZnBDC/CSC was characterized by XRD, FT-IR, solid-state 13C NMR, BET and SEM. The adsorption of ZnBDC/CSC for Cr(VI) and MO from aqueous solutions were studied at pH 5.0. The adsorption conditions, such as adsorption time and initial concentration of Cr(VI) and MO solutions were investigated. The results indicated that ZnBDC/CSC showed high adsorption capacity for both Cr(VI) (225 ± 4 mg g−1) and MO (202 ± 3 mg g−1), respectively. The adsorption of Cr(VI) on ZnBDC/CSC could be well described by Langmuir isotherm model, while MO followed Freundlich model. The adsorption kinetic of Cr(VI) and MO demonstrated a better fitness to the pseudo-second order kinetic model. Thermodynamic parameters (enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG)) demonstrated that the adsorption processes of Cr(VI) and MO on ZnBDC/CSC were exothermic, disordered and spontaneous at 298−318 K. The adsorption mechanism of ZnBDC/CSC for Cr(VI) could be mainly explained by electrostatic attraction and cation-π interaction, while for MO, it could be assigned to n-π and π-π interactions, electrostatic attraction and hydrogen bonding. ZnBDC/CSC could be recycled and reused for the removal of Cr(VI) and MO.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
