Magnetic recyclable metal-organic framework sheets grafted with curcumin for highly efficient adsorption and...

The contents of fluoride in drinking water should be limited to a safe range. Hence, design and development of a simple and efficient technology for adsorption and detection of fluoride is urgently required. We presented a curcumin in situ grafted MOF magnetic material (Fe₃O₄/MOF-Cur) for dual-functionalized applications of fluoride detection and adsorption. Owing to the electrostatic interaction, ligand exchange at the metal sites and boron-fluorine complexation, the adsorption capacity of Fe₃O₄/MOF-Cur for fluoride is 99.92 mg/g, and the detection limit is 1.17 μM. The fluoride adsorption behavior on different active units was further visualized by theoretical calculations. Favorable stability (79.52 mg/g after 5 adsorption-desorption cycles and insignificant change of fluorescence intensity within 30 days), mild reaction conditions (pH = 3-5) and excellent anti-interference ability promote the application of Fe₃O₄/MOF-Cur in real samples. Finally, the paramagnetic properties (29 emu/g) allow for easy recovery from water. These findings deepen the understanding on the design and development of dual-functionalized MOF materials, and prove the application potential of Fe₃O₄/MOF-Cur for the remediation of fluoride-related environmental pollution.