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

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.