Yu Cai-Xia, Jiang Wen, Lei Min, Yao Meng-Ru, Sun Xue-Qin, Wang Yanlong, Liu Wei, Liu Lei-Lei
School of Environmental and Material Engineering, Yantai University, Yantai, 264005, P. R. China.
State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, P. R. China.
Small. 2024 Jun;20(23):e2308910. doi: 10.1002/smll.202308910. Epub 2023 Dec 27.
The efficient removal of radioactive uranium from aqueous solution is of great significance for the safe and sustainable development of nuclear power. An ultrathin 2D metal-organic framework (MOF) nanosheet with cavity structures was elaborately fabricated based on a calix[4]arene ligand. Incorporating the permanent cavity structures on MOF nanosheet can fully utilize its structural characteristics of largely exposed surface area and accessible adsorption sites in pollutant removal, achieving ultrafast adsorption kinetics, and the functionalized cavity structure would endow the MOF nanosheets with the ability to achieve preconcentration and extraction of uranium from aqueous solution, affording ultrahigh removal efficiency even in ultra-low concentrations. Thus, more than 97% uranium can be removed from the concentration range of 50-500 µg L within 5 min. Moreover, the 2D nano-material exhibits ultra-high anti-interference ability, which can efficiently remove uranium from groundwater and seawater. The adsorption mechanism was investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) analysis, and density functional theory (DFT) calculations, which revealed that the cavity structure plays an important role in uranium capture. This study not only realizes highly efficient uranium removal from aqueous solution but also opens the door to achieving ultrathin MOF nanosheets with cavity structures, which will greatly expand the applications of MOF nanosheets.
从水溶液中高效去除放射性铀对于核电的安全与可持续发展具有重要意义。基于杯[4]芳烃配体精心制备了一种具有空腔结构的超薄二维金属有机框架（MOF）纳米片。在MOF纳米片上引入永久性空腔结构，能够在污染物去除过程中充分利用其大比表面积和可及吸附位点的结构特点，实现超快的吸附动力学，并且功能化的空腔结构将赋予MOF纳米片从水溶液中实现铀预富集和萃取的能力，即使在超低浓度下也能实现超高的去除效率。因此，在5分钟内，从50 - 500μg/L的浓度范围内可以去除超过97%的铀。此外，这种二维纳米材料表现出超高的抗干扰能力，能够有效地从地下水和海水中去除铀。通过X射线光电子能谱（XPS）、傅里叶变换红外（FT - IR）分析和密度泛函理论（DFT）计算对吸附机理进行了研究，结果表明空腔结构在铀捕获中起着重要作用。本研究不仅实现了从水溶液中高效去除铀，还为制备具有空腔结构的超薄MOF纳米片打开了大门，这将极大地拓展MOF纳米片的应用。
