Wang Junli, Luo Chen, Wang Wentao, Wang Hui, Liu Yao, Li Jianwei, Yan Taihong
Department of Radiochemistry, China Institute of Atomic Energy, Beijing 102413, China.
State Key Laboratory of Chemical Resource Engineering, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Nanomaterials (Basel). 2025 May 9;15(10):714. doi: 10.3390/nano15100714.
The separation of palladium from radioactive waste streams represents a critical aspect of the secure handling and disposal of such hazardous materials. Palladium, in addition to its radioactive nature, holds intrinsic value as a resource. Despite the urgency, prevailing adsorbents fall short in their ability to effectively separate palladium under highly acidic environments. To surmount this challenge, our research has pioneered the development of 1,3,5-tris(4-aminophenyl)benzene-2,5-Bis(methylthio)terephthalaldehyde COF (TAPB-BMTTPA-COF), a novel material distinguished by its remarkable stability and an abundance of sulfur-containing functional groups. Leveraging the pronounced affinity of the soft ligands' nitrogen and sulfur within its molecular architecture, TAPB-BMTTPA-COF demonstrates an exceptional capability for the selective adsorption of palladium. Empirical evidence underscores the material's swift adsorption kinetics, with equilibrium achieved in as little as ten minutes, and its broad tolerance to varying acidity levels ranging from 0.1 to 3 M HNO. Furthermore, TAPB-BMTTPA-COF boasts an impressive adsorption capacity, peaking at 343.6 mg/g, coupled with high selectivity in 13 interfering ions' environment and the ability to be regenerated, making it a sustainable solution. Comprehensive analyses, including Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), alongside Density Functional Theory (DFT) calculations, have corroborated the pivotal role played by densely packed nitrogen and sulfur active sites within the framework. These sites exhibit a robust affinity for Pd(II), which is the cornerstone of the material's outstanding adsorption efficacy. The outcomes of this research underscore the immense potential of COFs endowed with resilient linkers and precisely engineered functional groups. Such COFs can adeptly capture metal ions with high selectivity, even in the face of severe environmental conditions, thereby paving the way for the more effective and environmentally responsible management of radioactive waste.
从放射性废物流中分离钯是安全处理和处置此类危险材料的关键环节。钯除了具有放射性外，作为一种资源还具有内在价值。尽管情况紧急，但现有的吸附剂在高酸性环境下有效分离钯的能力不足。为了克服这一挑战，我们的研究率先开发了1,3,5-三（4-氨基苯基）苯-2,5-双（甲硫基）对苯二甲醛共价有机框架（TAPB-BMTTPA-COF），这是一种新型材料，以其卓越的稳定性和大量含硫官能团而著称。利用其分子结构中软配体的氮和硫的显著亲和力，TAPB-BMTTPA-COF展现出对钯的选择性吸附的卓越能力。实验证据强调了该材料迅速的吸附动力学，短短十分钟即可达到平衡，并且对0.1至3 M硝酸的不同酸度水平具有广泛的耐受性。此外，TAPB-BMTTPA-COF具有令人印象深刻的吸附容量，峰值为343.6 mg/g，在13种干扰离子的环境中具有高选择性以及可再生能力，使其成为一种可持续的解决方案。包括傅里叶变换红外光谱（FT-IR）和X射线光电子能谱（XPS）在内的综合分析，以及密度泛函理论（DFT）计算，证实了框架内密集排列的氮和硫活性位点所起的关键作用。这些位点对Pd(II)表现出强大的亲和力，这是该材料出色吸附效果的基石。这项研究的结果强调了具有弹性连接体和精确设计官能团的共价有机框架的巨大潜力。即使在恶劣的环境条件下，此类共价有机框架也能熟练地以高选择性捕获金属离子，从而为更有效且对环境负责的放射性废物管理铺平道路。
