Abstract：
As a new type of porous crystalline composite material, MOF-COF has shown great advantages in metal separation. Herein, a CoMOF-COF was designed for highly selective separation of trace Pb2+ ions. The designed CoMOF-COF has a high density of nitrogen-oxygen functional groups and can selectively separate metal ions. There is a strong affinity between the designed CoMOF-COF material and metal Pb2+ ions, which can be attributed to the ordered heterogeneous porous structure and large amounts of nitrogen-and oxygen-containing functional groups. The composite showed high adsorption selectivity for Pb2+ ions and had adsorption capacity of 33 mg g-1, with high chemical stability. Based on this solid phase extraction material, a high sensitivity detection method for Pb2+ ions was established, which has the detection limit of 37.3 ng L-1, precision of 1.9 %. Linear detection range is 0.2-10 ng mL-1, and the detection of Pb2+ ions in actual water samples was realized. Through this study, it is proved that the strong affinity between the designed CoMOF-COF materials and metal Pb2+ ions can be attributed to the soft and hard acid-base theory, which reveals the structure-activity relationship between the porous heterostructure of such materials and metal separation, providing a highly selective separation material for the separation of other environmental pollutants.
摘要：
作为一种新型的多孔结晶复合材料,MOF-COF在金属分离方面显示出巨大的优势。在这里，CoMOF-COF被设计用于高选择性分离痕量Pb2+离子。设计的CoMOF-COF具有高密度的氮-氧官能团，可以选择性地分离金属离子。设计的CoMOF-COF材料与金属Pb2+离子之间有很强的亲和力,这可以归因于有序的异质多孔结构和大量的含氮和氧官能团。该复合材料对Pb2+离子具有较高的吸附选择性,吸附容量为33mgg-1,具有较高的化学稳定性。基于这种固相萃取材料，建立了一种高灵敏度的Pb2+离子检测方法,检出限为37.3ngL-1，精密度为1.9%。线性检测范围为0.2-10ngmL-1,实现了实际水样中Pb2+离子的检测。通过这项研究,证明了所设计的CoMOF-COF材料与金属Pb2+离子之间的强亲和力可以归因于软酸碱理论和硬酸碱理论，揭示了这种材料的多孔异质结构与金属分离之间的结构-活性关系，为其他环境污染物的分离提供了高度选择性的分离材料。
