Magnetic Zr-MOFs nanocomposites for rapid removal of heavy metal ions and dyes from water.

Amino-decorated Zr-based magnetic Metal-Organic Frameworks composites (Zr-MFCs) were prepared by a facile and efficient strategy. The nano-sized Fe3 O4 @SiO2 core (about 15 nm) was coated with a shell of Zr-MOFs (about 5 nm) by means of in-situ growth. And, Fe3 O4 @SiO2 @UiO-66 and its amino derivatives (Fe3 O4 @SiO2 @UiO-66-NH2 and Fe3 O4 @SiO2 @UiO-66-Urea) were successfully prepared by using different precursors. The obtained Zr-MFCs were demonstrated to be efficient adsorbents for metal ions/organic dyes removal from aqueous solution, with high adsorption capacity and fast adsorption kinetics. It was found that the amine-decorated MFCs were highly efficient for metal ions/dyes removal compared to raw MFC-O. Among them, MFC-N exhibited the highest capacity for Pb2+ (102 mg g-1 ) and methylene blue (128 mg g-1 ), while MFC-O exhibited the highest capacity for methyl orange (219 mg g-1 ). Moreover, anionic and cationic dyes could be selectively separated and removed from the mixed solution just by adjusting the solution pH with Zr-MFCs as the adsorbents. And these Zr-MFCs materials can be easily regenerated by desorbing metal ions/organic dyes from the sorbents with appropriate eluents, and the adsorption capacity can be remained unchanged after 6 recycles. The obtained results demonstrated the great application potential of the prepared MFCs as fascinating adsorbents for water treatment.