Ultrafast and multiple heavy metal ions capture from wastewater by aminotriacetic acid-functionalized MOF-808

Current research on heavy metal adsorbents primarily focuses on eliminating particular heavy metal ions. Nevertheless, there remains a pressing demand for adsorbents capable of efficiently capturing a wide range of heavy metals found in actual wastewater. We report a metal–organic framework (MOF-808-NTA) functionalized with aminotriacetic acid (NTA), which has broad-spectrum capabilities for capturing heavy metal ions. Experiments with 15 distinct heavy metal ions, including hard (e.g., Cr 3+ ), soft (e.g., Hg 2+ ), and borderline Lewis metal ions (e.g., Pb 2+ ), found that the material achieved over 99 % removal efficiency in both individual ion and single-ion scenarios. Importantly, MOF-808-NTA exhibited ultrafast adsorption kinetics (removal >99 % within 30 s) for multiple metal ions, including Cr 3+ , Hg 2+ , and Pb 2+ , excellent selectivity (removal >95 %) when competing substances like Na + , Ca 2+ , and humic acid; and remarkable recyclability (removal >97.5 % after 5 cycles). Furthermore, spectrum analysis and theoretical calculation calculations indicate that the NTA groups in MOF-808-NTA serve as the primary sites for adsorption. The nitrogen and two oxygen atoms within the NTA groups create claw-like structures, which ensure exceptional capture of heavy metal ions. This work underscores the promise of MOF-808-NTA to function as a versatile material for capturing diverse heavy metals from wastewater.