氨基修饰金属有机骨架材料MIL-101(Fe)吸附水中Cr(VI)的研究

When the concentration of Cr(VI) exceeds the water standard, there will be a serious danger to the human health and environment. Metal-organic framework (MOF) material is regarded as a potential adsorbent in water treatment due to its large surface areas, diversified structure and easy modification. The amino-modified metal-organic framework MIL-101(Fe) is synthesised based on the cooperative effects of pore structure, functional groups and coordination. The adsorption performance of Cr(VI) on MIL-101(Fe)-NH2 will be investigated by regulating the structure of the adsorbent. The mechanism of amine groups effect on the adsorption of adsorbent will be established based on the structure activity relationship. The specific structure MIL-101(Fe)-NH2 and high performance adsorbent of removal Cr(VI) will be prepared. The adsorption-desorption mechanism of MIL-101(Fe)-NH2 to Cr(VI) will be revealed using the combination of active sites characterization, the adsorption-desorption kinetics and DFT simulation, which provides reference and guidance for the removal of Cr(VI) from aqueous solution.

水体中的Cr(VI)含量若超标，会严重危害人体健康和生态环境。金属-有机骨架材料比表面积大、结构多样、表面易修饰，是一类潜在优良的吸附材料。本研究基于MIL-101(Fe)的孔结构、功能基团、配位作用等多种协同效应，制备氨基修饰的金属有机骨架材料MIL-101(Fe)-NH2。通过吸附剂的结构调控，系统研究其对Cr(VI)的吸附性能；结合吸附剂的构效关系，建立氨基官能团对MIL-101(Fe)材料吸附的影响机制，实现Cr(VI)吸附剂的可控合成，获得高性能的Cr(VI)吸附剂。通过吸附活性位表征、吸附/解吸动力学和DFT模拟相结合的研究手段，揭示MIL-101(Fe)-NH2对Cr(VI)的吸附/解吸作用本质，为MOFs材料在吸附处理水体中重金属污染物提供借鉴和指导。

水体中的Cr(VI)含量若超标，会严重危害人体健康和生态环境。本研究基于MIL-101(Fe)的孔结构、功能基团、配位作用等多种协同效应，采用原位修饰和后修饰方法制备了氨基修饰的金属有机骨架材料MIL-101(Fe)-NH2并用于水中Cr(VI)去处。原位修饰的材料形貌规则、结晶度高；氨基数量增加导致其比表面积减小，形成了更大孔容和孔径，但其热稳定性相差不大。MIL-101(Fe)-NH2均表现出良好的优惠吸附特征，其中N-9性能最为优异，在5min内其吸附容量可达到288.8 mg∙g-1，表明氨基修饰可以提高其去处Cr(VI)能力；随溶液pH增加，吸附容量略有降低，但具有更宽的pH适用范围；共存离子的影响不显著，材料循环使用效率高，表明该吸附材料对实际水体中Cr(VI)具有良好的富集与转运能力，在Cr(VI)污染水体快速修复方面具有潜在应用价值。采用吸附活性位表征、吸附/解吸动力学和DFT模拟相结合的研究手段，揭示了MIL-101(Fe)-NH2对Cr(VI)的吸附机制，为MOFs材料在吸附处理水体中重金属污染物提供借鉴和指导。