One-step solvothermal synthesis of Fe3O4@Carbon composites and their application in removing of Cr (VI) and Congo red.

Abstract Fe 3 O 4 @C nano-adsorption was prepared by a simple one-step solvothermal synthesis method using Fe (NO 3) 3 、cyclodextrin as raw materials, meanwhile urea as an alkali source. The obtained samples were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, and Brunauer-Emmett-Teller. The adsorption behavior of the Fe 3 O 4 @C toward Cr (VI) and Congo red was also studied. The core-shell structure Fe 3 O 4 @C exhibited large specific surface area of 112.91 m2 g−1. The prepared Fe 3 O 4 @C samples demonstrated typical ferromagnetic behavior and high removal capacity in removing the toxic Cr (VI) ions and organic pollutant CR from wastewater, together with facile magnetic separability and good recyclability. Equilibrium adsorption performance was conducted by using the Langmuir and Freundlich model and Freundlich model could simulate the adsorption process of Congo red and Cr (VI) better. The maximum adsorption capacity of Cr (VI) and Congo red was 33.35 mg g−1 and 262.72 mg g−1 by calculation. [ABSTRACT FROM AUTHOR]