Highly Sensitive and Selective Uranium Detection in Natural Water Systems Using a Luminescent Mesoporous Metal-Organic Framework Equipped with Abundant Lewis Basic Sites: A Combined Batch, X-ray Absorption Spectroscopy, and First Principles Simulation Investigation
Highly Sensitive and Selective Uranium Detection in Natural Water Systems Using a Luminescent Mesoporous Metal-Organic Framework Equipped with Abundant Lewis Basic Sites: A Combined Batch, X-ray Absorption Spectroscopy, and First Principles Simulation Investigation
复制标题
使用配备丰富路易斯碱性位点的发光介孔金属有机框架在天然水系统中进行高灵敏度和选择性铀检测：组合批次、X 射线吸收光谱和第一原理模拟研究
DOI：
10.1021/acs.est.6b06305
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发表时间：
2017-04-04
影响因子：
11.4
通讯作者：
Wang, Shuao
中科院分区：
文献类型：
--
作者：
Liu, Wei;Dai, Xing;Wang, Shuao
铀不仅是核工业的战略资源，而且是一种全球性的高毒性污染物。尽管已经建立了几种检测水中铀酰离子的策略，但寻找具有高灵敏度、选择性和稳定性的新型铀传感器材料仍然是一个挑战。本文介绍了一种水解稳定的介孔铽基MOP材料化合物1，其孔道尺寸为27埃× 23埃，具有丰富的暴露的刘易斯碱中心，其发光强度可以被铀酰离子有效地选择性地猝灭。在去离子水中的检出限达到0.9 μ g/L，远低于美国环保署定义的饮用水中30 μ g/L的最大污染标准，使得化合物1成为目前唯一能达到这一目标的MOF材料。更重要的是，这种材料在检测天然水系统中的铀酰离子方面表现出很强的能力，例如湖水和海水，pH值被调节到4，其中存在大量过量的竞争离子。独墅湖水和海水中铀酰的检出限分别为14.0和3.5 μ g/L。这种高检测能力源于铀酰离子选择性结合到MOF材料的刘易斯碱性位点上，如同步辐射扩展X射线吸收精细结构、X射线吸收近边结构和第一性原理计算所证明的，进一步导致铀酰离子和MOF骨架之间的有效能量转移。
Uranium is not only a strategic resource for the nuclear industry but also a global contaminant with high toxicity. Although several strategies have been established for detecting uranyl-ions in water, searching for new uranium sensor material with great sensitivity, selectivity, and stability remains a challenge. We introduce here a hydrolytically stable mesoporous terbium(III)-based MOP material compound 1, whose channels are as large as 27 angstrom x 23 angstrom and are equipped with abundant exposed Lewis basic sites, the luminekence intensity of which can be efficiently and selectively quenched by uranyl ions. The detection limit in deionized water reaches 0.9 mu g/L, far below the maximum contamination standard of 30 mu g/L in drinking water defined by the United States Environmental Protection Agency, making compound 1 currently the only MOF material that can achieve this goal. More importantly, this material exhibits great capability in detecting uranyl ions in natural water systems such as lake water and seawater with pH being adjusted to 4, where huge excesses of competing ions are present. The uranyl detection limits in Dushu Lake water and in seawater were calculated to be 14.0 and 3.5 mu g/L, respectively. This great detection capability originates from the selective binding of uranyl ions onto the Lewis basic sites of the MOF material, as demonstrated by synchrotion radiation extended X-ray adsorption fine structure, X-ray adsorption near edge structure, and first principles calculations, further leading to an effective energy transfer between the uranyl ions and the MOF skeleton.