Construction of magnetic bifunctional β-cyclodextrin nanocomposites for adsorption and degradation of persistent organic pollutants

•Fe3O4@β-CD-CDI was synthesized by coordination interaction between Zn ions and β-CD-CDI ligands.•This composite had a satisfactory removal efficiency for BPA.•The polymer layer was introduced to enhance the structure stability.•The magnetic core facilitates easy separation and recycling.•The composites can as heterogeneous catalyst to removal BPA through Fenton-like reaction. Herein, we report a novel magnetic bifunctional β-cyclodextrin nanocomposite (Fe3O4@β-CD-CDI) based on metal coordination, which may be used for adsorption and degradation of persistent organic pollutants in aqueous solution. More importantly, N,N’-carbonyldiimidazole (CDI) functionalized β-CD ligand (β-CD-CDI) was assembled on the surface of Fe3O4 by Zn-N interaction. The results of kinetic and isothermal adsorption model investigation indicated that the adsorption rate and capacity of Fe3O4@β-CD-CDI were better than other materials, suggesting the effective accessibility of adsorption sites. We further confirmed that Fe3O4@β-CD-CDI can be used as heterogeneous catalyst to remove BPA through Fenton-like reaction in the presence of hydrogen peroxide (H2O2). Moreover, the material effectively alleviated the secondary pollution owing to the existence of β-CD inner cavity. This study indicated that the magnetic Fe3O4@β-CD-CDI material has great potential applications in wastewater purification containing persistent organic pollutants.