金属有机框架材料吸附分离水中铀的应用

Application of metal-organic frameworks in adsorption and separation of uranium from water

金属有机框架材料(metal-organic frameworks,MOFs)具有极高的比表面积和孔隙率,结构可设计调控,但在水相吸附分离方面存在水稳定和选择吸附性较差、分离困难、合成与再生成本偏高等问题。针对MOFs的缺陷,可以通过有目的的功能化改性从而提升其对目标污染物的吸附性能。本文介绍了MOFs的结构优势,分析了水稳定性的影响因素和判断手段,简述了具有代表性的高水稳定性MOFs材料的特性;根据MOFs改性方法的分类回顾了MOFs及改性MOFs在去除水相中放射性铀的应用;基于不同分析技术探讨了MOFs与铀酰离子的吸附机理;提出推动MOFs在吸附铀方面规模化应用发展的核心是合成高稳定性MOFs,通过改性提高MOFs的选择吸附性能和再生性以及深入研究吸附机理。

Metal-organic frameworks (MOFs) have extremely high surface area and porosity,and their structures can be designed and regulated.However,there are some problems in its adsorption and separation in aqueous phase,such as poor water stability,poor adsorption selectivity,difficult separation from water,high cost of synthesis and regeneration.In light of this,MOFs can be functionalized purposefully to improve the adsorption performance on target pollutants.This review introduces the structural advantages of MOFs,analyzes the influencing factors and judgment methods of MOFs water stability,and briefly describes the characteristics of representative highly water stable MOFs materials.Special emphasis is put on the applications of different MOFs and modified MOFs in the removal of radioactive uranium from aqueous phase.Based on different analytical techniques,the adsorption mechanism of uranyl ions on MOFs was discussed.Finally,it is proposed that the key to promote the large-scale application of MOFs in uranium adsorption is to synthesize highly stable MOFs,improve the adsorption selectivity and regenerability through modification,and to study the adsorption mechanism in-depth.