Uranium is a key element in the nuclear industry and also a global environmental contaminant with combined highly toxic and radioactive. Currently, the materials based on post-modification of amidoxime have been developed for uranium detection and adsorption. However, the affinity of amidoxime group for vanadium is stronger than that of uranium, which is the main challenge hindering the practical application of amidoxime-based adsorbents. Herein, we synthesized a fluorescent covalent organic framework (TFPPy-BDOH) through integrating biphenyl diamine and pyrene unit into the π-conjugated framework. TFPPy-BDOH has an excellent selectivity to uranium due to the synergistic effect of nitrogen atom in the imine bond and hydroxyl groups in conjugated framework. It can achieve ultra-fast fluorescence response time (2 s) and ultra-low detection limit (8.8 nM), which may be attributed to its intrinsic regular porous channel structures and excellent hydrophilicity. More excitingly, TFPPy-BDOH can chemically reduce soluble U (VI) to insoluble U (IV), and release the binding site to adsorb additional U (VI), achieving high adsorption capacity of 982.6 ± 49.1 mg g⁻¹. Therefore, TFPPy-BDOH can overcome the challenges faced by current amidoxime-based adsorbents, making it as a potential adsorbent in practical applications.

铀是核工业的关键元素，也是具有高毒性和放射性的全球环境污染物。目前，基于偕胺肟后改性的材料已被开发用于铀的检测和吸附。然而，偕胺肟基团对钒的亲和力强于铀，这是阻碍偕胺肟基吸附剂实际应用的主要挑战。在此，我们通过将联苯二胺和芘单元整合到π-共轭框架中合成了荧光共价有机框架（TFPPy-BDOH）。由于亚胺键中的氮原子和共轭骨架中的羟基的协同作用，TFPPy-BDOH对铀具有优异的选择性。可实现超快的荧光响应时间（2 s）和超低的检测限（8. 8 nM），这可能归因于其固有的规则多孔通道结构和优异的亲水性。更令人兴奋的是，TFPPy-BDOH 可以将可溶性 U (VI) 化学还原为不溶性 U (IV)，并释放结合位点以吸附额外的 U (VI)，实现 982.6 ± 49.1 mg g 的高吸附容量^-1。因此，TFPPy-BDOH可以克服目前偕胺肟基吸附剂所面临的挑战，使其成为实际应用中的潜在吸附剂。