The development of novel porous materials as adsorbents for highly effective separation of thorium from ore or nuclear wastewater co-existing with uranium and rare earth elements is one of the most desirable methods but remains challenging. In this work, we prepare a N,O-functionalized two-dimensional covalent organic framework (2D COF), namely TAPT-DHTA, with a permanent porous structure and plenty of nitrogen and oxygen adsorption sites throughout the skeletons, which displays an ultrahigh Th(IV) saturated adsorption capacity of 1394 mg g (at pH = 4.0), higher than all adsorbents reported so far. Moreover, the TAPT-DHTA COF has a large distribution coefficient () of up to 5.2 × 10 mL g, implying its extremely strong affinity for Th(IV) due to the collaborative coordination interactions between N/O atoms and Th(IV) as well as their specific binding mechanism. The distinguished adsorption behavior of the TAPT-DHTA COF affords an important platform for highly selective separation of Th(IV) from uranium and rare earth elements, thereby shedding some light on the design of novel adsorbents for thorium separation in the thorium fuel cycle.

中文翻译：

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超高效率 N,O 功能化共价有机框架，用于从铀和稀土元素中吸附钍

开发新型多孔材料作为吸附剂，用于从与铀和稀土元素共存的矿石或核废水中高效分离钍，是最理想的方法之一，但仍然具有挑战性。在这项工作中，我们制备了一种N,O功能化的二维共价有机骨架（2D COF），即TAPT-DHTA，它具有永久的多孔结构，整个骨架具有大量的氮和氧吸附位点，表现出超高的Th （IV）饱和吸附容量为1394 mg g（pH = 4.0），高于迄今为止报道的所有吸附剂。此外，TAPT-DHTA COF具有高达5.2×10 mL g的大分配系数（），这意味着由于N/O原子和Th（IV）之间的协同配位相互作用，其对Th（IV）具有极强的亲和力以及它们的具体结合机制。 TAPT-DHTA COF 独特的吸附行为为从铀和稀土元素中高选择性分离 Th(IV) 提供了重要平台，从而为钍燃料循环中用于钍分离的新型吸附剂的设计提供了一些线索。