Constructing Carbon-Coated Fe3O4 Hierarchical Microstructures with a Porous Structure and their Excellent Cr(VI) Ion Removal Properties

Abstract Here, a facile solvothermal method coupled with an annealing strategy is developed to synthesize Fe3O4/carbon (Fe3O4@C) magnetic composite microstructures with different morphologies, including flower-like, hollow spheres and egg-like. Owing to the unique multi-porous and hollow structure, the as-prepared hierarchical Fe3O4@C hollow microspheres composite exhibit appealing performance as an absorbent of Cr(VI) ions in aqueous solution, delivering a high capacity of ca.197.2mg/g. Furthermore, the magnetic Fe3O4 ‘‘core’’ in composite hierarchical microstructures makes them easy to separate from aqueous systems by magnetic separation, the layer of carbon effectively prevents agglomerations of magnetic nanoparticles and expands their range of applications. The excellent Cr(VI) ions adsorbent activities of the Fe3O4@C magnetic composite microstructures would have a potential adsorbing material application in environmental purification.