功能化介孔复合金属有机框架的制备及其对有机污染物的富集、分析检测

This project focuses on the synthesis of functionalized mesoporous metal-organic frameworks composites possessing ultrahigh specific surface areas. Employing large size of organic ligands or cationic surfactant as soft templates, MOFs with mesoporous structure were obtained. Based on nanoscale assembly technology, core-shell structured magnetic MOFs or MOFs loading with Au nanoparticles were prepared. The mesoporous MOFs composites were functionalized via coordination, covalent interactions, or solvent-assisted ligand incorporation. After that, the application potential of the modified mesoporous MOFs composites as solid-phase extraction adsorbents was investigated for the efficient extraction and rapid analysis of organic contaminants from environmental or biological samples. These MOFs composites have ultrahigh surface areas and uniform meso-pores, endowing extremely high adsorption capacity and fast adsorptive rate to organic pollutants. The mesopores in MOFs can prevent the macromolecules (such as humic acids, proteins) from entering by size exclusion, thus the extraction efficiency of trace level of target organic pollutants was not influenced by the abundant coexisting natural organic matter in sample matrix. Combined the excellent extraction performance of the functionalized mesoporous MOF composites to targets with the HPLC-MS, GC-MS, or MALDI-TOF-MS detection technique, the efficient, sensitive and rapid pretreatment and analysis of trace contaminants in environmental or biological samples can be achieved.

项目旨在合成具有超大比表面积的功能化介孔复合金属有机框架（MOFs）材料。采用大尺寸有机配体或以阳离子表面活性剂为软模板，得到具有介孔孔道的MOFs；通过纳米组装技术，制备出核壳式、镶嵌式等复合磁性MOFs或负载纳米金颗粒的MOFs；通过配位、共价修饰以及溶剂辅助配体交换等方法对介孔复合MOFs进行功能化修饰。以修饰后的介孔MOFs为固相萃取吸附剂，探讨其在环境或生物样品中有机污染物的高效萃取富集及快速检测中的应用。该类材料的超大比表面积和介孔孔道使其对有机污染物具有超高吸附容量和较快的吸附速率；介孔孔道对环境介质中大分子的蛋白质、腐殖酸等干扰物质具有尺寸排阻作用，避免了这些大量共存天然有机质对痕量目标污染物富集的干扰。将功能化介孔复合MOFs的高效萃取富集与HPLC-MS、GC-MS、MALDI-TOF-MS等检测技术联用，可以实现对环境或生物样品中微量有机污染的高效、灵敏、快速分析。

按照项目研究计划，基于金属有机框架（MOF）材料，包括Zn-MOF、Fe-MOF及空心Fe/Zn-MOF，开发了MOF纳米反应器、多级有序介孔碳及零价铁/碳复合材料。该类材料对污水中的氯酚、苯酚、甲基橙和亚甲基蓝等高毒污染物具有强富集和吸附去除能力。利用Fenton催化技术或铁-碳微电解技术-Fenton催化等高级氧化技术，该类材料可以高效、持续地降解水中的有机污染物。为了克服MOF材料化学稳定性低、疏水性弱、对污染物富集吸附能力低、光响应差等缺点，通过分子设计和精确构筑，定向合成了一系列具有更强化学稳定性和疏水性的COF、MOF/COF及COF/COF复合材料。这些COFs材料的超大比表面积、全共轭苯环结构、强疏水性及光响应性能等赋予了其对污染物优越的富集吸附能力及良好的可见光响应能力和光生载流子传导效率，从而可以快速、高效地促进污染物的光催化降解及矿化。另外，基于廉价经济的均苯三甲醛和对苯二胺构筑的COFs材料对全氟/多氟化合物具有较强的吸附能力和优越的表面辅助激光解析（SALDI）基质效应，以其为SALDI基质和吸附剂，建立了COFs富集和表面辅助激光解析/离子化-飞行时间质谱（SALDI-TOF MS）一体化方法，PFOS的检测限可达到亚ppt级。通过层层组装技术，制备了以聚偏氟乙烯膜为支撑体的负载聚多巴胺层和纳米金颗粒的多功能纳米金-聚多巴胺-聚偏氟乙烯膜。该膜片既对有机污染物具有强富集能力，又具有优越的基质辅助功能，进而建立了基于该膜片的固相萃取（SPE）-SALDI-TOF MS一体化方法，可在30min实现对水样中污染物的快速检测。发表SCI论文17篇，影响因子大于5.0的16篇，大于10的10篇，申请专利7项，其中授权5项。