The selective separation of thorium from rare earth elements and uranium is a critical part of the development and application of thorium nuclear energy in the future. To better understand the role of different N sites on the selective capture of Th(IV), we design an ionic COF named Py-TFImI-25 COF and its deionization analog named Py-TFIm-25 COF, both of which exhibit record-high separation factors ranging from 10² to 10⁵. Py-TFIm-25 COF exhibits a significantly higher Th(IV) uptake capacity and adsorption rate than Py-TFImI-25 COF, which also outperforms the majority of previously reported adsorbents. The selective capture of Py-TFImI-25 COF and Py-TFIm-25 COF on thorium is via Th-N coordination interaction. The prioritization of Th(IV) binding at different N sites and the mechanism of selective coordination are then investigated. This work provides an in-depth insight into the relationship between structure and performance, which can provide positive feedback on the design of novel adsorbents for this field.

从稀土元素和铀中选择性分离钍是未来钍核能开发和应用的关键部分。为了更好地了解不同N位点对Th(IV)选择性捕获的作用，我们设计了一种名为Py-TFImI-25 COF的离子COF及其名为Py-TFIm-25 COF的去离子类似物，两者均表现出创纪录的高水平分离因子范围从 10 ²到 10 ⁵。Py-TFIm-25 COF 表现出比 Py-TFImI-25 COF 显着更高的 Th(IV) 吸收能力和吸附率，其性能也优于大多数先前报道的吸附剂。Py-TFImI-25 COF 和 Py-TFIm-25 COF 在钍上的选择性捕获是通过 Th-N 配位相互作用实现的。然后研究了 Th(IV) 在不同 N 位点结合的优先顺序以及选择性配位的机制。这项工作深入洞察了结构与性能之间的关系，可以为该领域新型吸附剂的设计提供积极的反馈。