Enhanced Cr(vi) removal by hierarchical CoFe2O4@SiO2–NH2via reduction and adsorption processes

Abstract

In order to realize the highly effective removal of toxic Cr(VI), 3D porous CoFe₂O₄@SiO₂–NH₂ has been successfully fabricated. As expected, the saturated adsorption capacity of the resulting CoFe₂O₄@SiO₂–NH₂ composite towards Cr(VI) can reach up to 126.8 mg g⁻¹, superior to most Fe-containing adsorbents. In addition, the obtained CoFe₂O₄@SiO₂–NH₂ exhibits excellent Cr(VI) removal performance after four consecutive adsorption–desorption cycles. The exceptional Cr(VI) removal performance can be ascribed to its excellent electrostatic effect as well as the reduction process originating from the –CH group. Therefore, the hierarchically porous CoFe₂O₄@SiO₂–NH₂ is expected to be highly applicable in Cr(VI)-contaminated water remediation.