Magnetic beads embedded in poly (sodium-p-styrenesulfonate) and ZIF-67: Removal of nitrophenol from water

Owing to the diverse structures and unique characteristics of MOFs, the combination of magnetic particles with porous MOFs is an attractive way for rapid and efficient extraction of organic pollutions from water. In this work, the magnetic porous composites, Fe3O4-PSS@ZIF-67 (PSS, poly (sodium-p-styrenesulfonate)), were prepared. The obtained composites exhibit core-shell structure, for which the spherical Fe3O4 particles as core are embedded in ZIF-67 shell. The existence of SO3- anions on poly (sodium-p-styrenesulfonate) is the key factor for the uniform coating of ZIF-67 on Fe3O4 particles. Poly (sodium-p-styrenesulfonate) providing enough chelating sites (-SO3-) for Co2+ which could further coordinate with 2-methylimidazole to form ZIF-67. This work further studied the adsorption property of 2-nitroresorcinol in aqueous solution, using Fe3O4-PSS@ZIF-67 as adsorbents. The equilibrium adsorption capacity for 2-nitroresorcinol is up to 52.50 mg g(-1). The adsorption kinetics were investigated. The mechanism could be attributed to the electrostatic interaction between 2-nitroresorcinol and Fe3O4-PSS@ZIF-67 composites.