Hierarchical Porous Amidoximated Metal–Organic Framework for Highly Efficient Uranium Extraction

Abstract

Abstract With the rapid development of industry and technology, high‐efficiency extraction of uranium from seawater is a research hotspot from the aspect of nuclear energy development. Herein, a new amidoximated metal–organic framework (UiO‐66‐DAMN‐AO) constructed through a novel organic ligand of 2‐diaminomaleonitrile‐terephthalic acid (BDC‐DAMN) is designed via one‐step post‐synthetic methods (PSM), which possess the merit of abundant multiaffinity sites, large specific surface area, and unique porous structure for efficient uranium extraction. Adopting one‐step PSM can alleviate the destruction of structural stability and the reduction of the conversion rate of amidoxime groups. Meanwhile, introducing the BDC‐DAMN ligand with abundant multiaffinity sites endow UiO‐66‐DAMN‐AO with excellent adsorption ability ( Q m = 426.3 mg g −1 ) and selectivity. Interestingly, the UiO‐66‐DAMN‐AO has both micropores and mesopores, which may be attributed to the partial etching of UiO‐66‐DAMN‐AO during the amidoximation. The presence of mesopores improves the mass transfer rate of UiO‐66‐DAMN‐AO and provides more exposed active sites, favoring the adsorption of uranium on UiO‐66‐DAMN‐AO. Thus, this study provides a feasible strategy for modifying metal–organic framework (MOFs) with plentiful amidoxime groups and the promising prospect for MOF‐based materials to adsorb uranium from ocean.