单线态氧介导的金属卟啉有机框架材料高效去除污染物及动力学研究

发布时间：2018-06-18 04:55

本文选题：金属卟啉框架材料 + 单线态氧　；参考：《南京师范大学》2017年硕士论文

【摘要】：多孔金属有机骨架(MOFs)材料具有永久的孔隙率,大的比表面积,优良的热稳定性及易于修饰的特性。近年来,将光敏剂卟啉作为有机配体构建具有特殊功能的金属卟啉框架材料已成为研究热点。这种卟啉-MOF不仅具有高吸附性能并且在可见光照下可有效产生单线态氧(1O2)。基于此,我们首先利用稳定的锆-卟啉金属有机骨架材料超高吸附和单线态氧介导的协同作用高效去除双酚A(BPA),其次我们进一步深入研究金属卟啉框架材料的孔结构及晶粒尺寸与单线态氧产生动力学间的关系,并对单线态氧产生速率的差异性做出理论解释。这种基于可见光照下以卟啉-MOF为催化剂产生单线态氧来催化降解污染物的作用机理及其后续的单线态氧产生的动力学研究,不仅可提高对此类反应的认识水平,同时对基于发展单线态氧的卟啉-MOF催化剂有一定的指导意义。具体内容分述如下:1、基于稳定的锆-卟啉金属有机骨架材料超高吸附和单线态氧介导的协同作用高效去除BPA双酚A作为世界卫生组织公布的23种重要的内分泌干扰物之一,对人类健康带来严重威胁。本研究应用一种基于锆-卟啉构建的金属有机骨架材料(MOF)作为催化剂用来富集水中双酚A(BPA)并在可见光照下进行催化降解。本研究探索了 PCN-222吸附BPA的吸附量、吸附动力学以及在室温及中性pH下PCN-222催化BPA的机理。PCN-222吸附BPA最大吸附量高达487.69±8.37 mgg-1 (目前为止最大吸附量)。在可见光照下,PCN-222作为单线态氧产生的介质以此来催化降解100 mg L-1 BPA,催化速率常数为(3.9±0.2)×10-3mgmin-1。结果表明,在治理污染物BPA中,PCN-222既表现出良好的吸附性能又展现出优良的光催化活性。与之前降解BPA的方法相比,我们提出治理污染物的方法具有更高效率和可重复利用率。2、基于金属卟啉框架材料单线态氧产生的尺寸依赖动力学研究由于卟啉优越的光敏性,卟啉-MOF可有效产生单线态氧。单线态氧产生的动力学与MOFs微纳颗粒的尺寸有关。本研究利用水热法通过控制反应溶剂、反应时间、反应温度及酸调节剂等参数合成了一系列不同尺寸的卟啉-MOF材料。通过使用单线态氧淬灭剂DPBF来监测单线态氧的产生,进而探究卟啉-MOF的孔结构和晶粒尺寸对1O2产生速率的影响。此外,我们用Si02晶粒包裹卟啉-MOF材料的外表面来探究的1O2产生方式。实验表明,可见光照下1O2产生于卟啉-MOF中并且纳米级的PCN-222具有最高的产生1O2能力,其1O2产生速率常数k=0.047s-1,此外卟啉-MOF晶粒尺寸及孔道结构均影响其产生1O2活性,当卟啉-MOF孔径越大,孔结构位阻越小时,晶粒尺寸对其产生1O2速率影响不明显;当卟啉-MOF孔径越小,孔结构位阻越大时,晶粒尺寸对其产生1O2速率影响显著。
[Abstract]:Porous metal-organic framework (MOF) materials have permanent porosity, large specific surface area, excellent thermal stability and easy modification. In recent years, the preparation of metalloporphyrin frame materials with special functions by using Guang Min as organic ligands has become a research hotspot. This kind of porphyrin-MOF not only has high adsorption performance but also can effectively produce singlet oxygen oxide 1O _ 2 ~ (2 +) under visible light. Based on this, At first, we use the stable zirconium porphyrin metalloporphyrin metal skeleton material super high adsorption and the single line oxygen mediated synergistic action to remove BPAN efficiently. Secondly, we further study the pore structure and grain size of the metalloporphyrin frame material. The relationship between size and singlet oxygen generation kinetics, The difference of singlet oxygen production rate is explained theoretically. The mechanism of catalytic degradation of pollutants using porphyrin-MOF as catalyst under visible light and the kinetics of subsequent single-line oxygen generation can not only improve the understanding of such reactions. At the same time, it has certain guiding significance for porphyrin-MOF catalyst based on developing singlet oxygen. The specific contents are as follows: 1. The removal of BPA bisphenol A (BPA) as one of the 23 important endocrine disruptors published by the World Health Organization (WHO) is based on the ultrahigh adsorption of stable zirconium porphyrin metallic-organic framework materials and the synergistic effect of singlet oxygen mediated removal. Pose a serious threat to human health. In this study, a metal-organic framework material based on zirconium porphyrin (MOF) was used as catalyst for the enrichment of bisphenol A (BPA) in water and its degradation under visible light. In this study, the adsorption capacity and kinetics of PCN-222 adsorbed BPA and the mechanism of catalytic BPA adsorption at room temperature and neutral pH were investigated. The maximum adsorption capacity of PCN-222 was 487.69 卤8.37 mgg-1 (up to now, the maximum adsorption capacity was 487.69 卤8.37 mgg-1). Under visible light, PCN-222 was used as the medium for the production of singlet oxygen to catalyze the degradation of 100 mg L-1 BPA.The catalytic rate constant was 3.9 卤0.2) 脳 10-3mgmin-1. The results showed that the adsorptive property and photocatalytic activity of Pn-PCN-222 in the treatment of BPA were good. Compared with the previous degradation methods, we proposed a more efficient and repeatable method for the treatment of pollutants. Based on the size dependence kinetics of singlet oxygen generation in metalloporphyrin frame materials, porphyrin is superior to porphyrin because of its superior Guang Min properties. Porphyrin-MOF can effectively produce singlet oxygen. The kinetics of singlet oxygen production is related to the size of MOFs nanocrystalline particles. A series of porphyrin-MOF materials of different sizes were synthesized by hydrothermal method by controlling reaction solvent, reaction time, reaction temperature and acid regulator. The effect of pore structure and grain size of porphyrin-MOF on the production rate of 1O2 was investigated by using single linear oxygen quenching agent DPBF to monitor the production of singlet oxygen. In addition, the formation of 1O _ 2 on the outer surface of porphyrin-MOF materials was investigated by using Si02 grain encapsulated porphyrin-MOF materials. The experimental results show that 1O2 is produced in porphyrin-MOF under visible light and the nano-scale PCN-222 has the highest ability to produce 1O2, and the rate constant of 1O2 production is 0.047s-1.Furthermore, the grain size and pore structure of porphyrin-MOF affect the activity of 1O _ 2 production. When porphyrin-MOF pore size is larger, the pore structure steric resistance is smaller, the effect of grain size on 1O _ 2 generation rate is not obvious, and when porphyrin-MOF pore size is smaller and pore structure steric resistance is larger, the grain size has a significant effect on 1O _ 2 generation rate.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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