Synthesis of Fe3O4@Zn-BDC nanocomposite for the removal of MB from aqueous solution

Coordination polymers (CPs) are a significant platform for dye adsorption. Designing Fe3O4@CP nanocomposites as easy-recoverable adsorbents could facilitate their recycling. In this research, a core-shell Fe3O4@CP nanocomposite was prepared for methylene blue (MB) adsorption and removal from aqueous solutions. The obtained nanocomposite consists of Fe3O4 core and coordination polymer shell constructed from Zn2+ and benzene-1,4-dicarboxylic acid (H2-BDC) which formed with layer-by-layer assembly. The formation of the core-shell nanostructure was approved with various physicochemical techniques. The microscopy results confirmed a core-shell nanostructure for Fe3O4@CP nanocomposite that shell thickness is about 5–7 nm. The adsorption experiments indicated that Fe3O4@CP nanocomposite not only adsorbed more than 86% of MB only after 2 min, it significantly could be separated magnetically and reused without evident loss of adsorption efficiency after four cycles.