基于含氮、氧有机配体构筑的多孔晶态材料的合成、结构及光催化性能研究

发布时间：2018-04-28 09:59

本文选题：金属—有机骨架材料 + 六核钴簇　；参考：《东北师范大学》2017年硕士论文

【摘要】：金属—有机骨架材料(Metal-Organic Frameworks,MOFs)作为多孔材料领域的新型材料,在九十年代初期开始进入大众视野,它是一类含有特定官能团的有机配体和无机金属离子或金属簇通过自组装方式构筑的具有特定结构的多孔材料。正是由于其独特的有机-无机杂化构成模式,该材料的孔道形状和孔径尺寸可以被系统的调节,官能团易于被修饰。MOFs更是凭借其超高的比表面积、较高的孔隙率和特殊功能化的孔道表面在气体储存和分离、光学、电磁材料、化学传感、催化和生物医学领域得到广泛应用。近几年,随着MOFs在多孔材料领域的迅猛发展,大量具有特殊结构的MOFs材料被合成出来,该材料的发展也逐渐从单纯的设计合成具有独特结构的MOFs材料转向以功能为导向的MOFs材料的合成,通过合理的设计和调控来获得具有特定性能的功能性多孔材料。最初MOFs材料的结构研究为MOFs的功能化研究提供了必要的基础,使MOFs的功能化研究迅速成为多孔材料领域的研究热点。虽然MOFs材料在众多领域已表现出优异的性能,但是在一些领域依然存在着重要的问题需要研究探讨。因此,设计合成具有特殊结构和所需功能的MOFs材料在促进新型功能性多孔材料发展方面具有重大意义。本文中,我们选用4,4-联吡啶和三甲酸三苯胺有机配体,在溶剂热条件下设计合成了一例基于含氮、含氧有机配体构筑的三维(3D)多孔六核钴簇MOF材料[Co_3(NTB)(4,4'-bpy)_(1.5)(OH)_3]·DEF(Co_6-MOF)NTB=三甲酸三苯胺,4,4'-bpy=4,4'-联吡啶Co_6-MOF具有传统的三维柱撑结构,具有较大的碳纳米管孔道,拓扑结构表现为3,8连接网络结构,拓扑符号为(4~3)2(4~6.6~18.8~4)。正是由于该MOF材料拥有柱撑结构、较大的孔道和较高的比表面积,其对N_2和CO_2表现出很好的吸附作用。此外,该MOF材料表现出很好的耐酸、耐碱性能,并且在空气中可以稳定存在。由于该MOF材料中独特的六核钴簇结构的存在,使其表现出较好的反铁磁性。该MOF材料显著的特点在于六核钴簇与配体间的特殊连接使其在光催化CO_2还原中表现出较好的催化性能。本文中,我们对该MOF材料的光催化CO_2还原催化性能进行了深入的研究探讨,对其催化机理进行了推测,并通过理论计算对推测的催化机理进行了验证。
[Abstract]:Metal-Organic frameworks (MOFs), a new type of porous material, has been in public view since the early 1990s. It is a kind of organic ligands with specific functional groups and inorganic metal ions or metal clusters, which are self-assembled porous materials with specific structures. It is precisely because of its unique organic-inorganic hybrid structure that the pore shape and pore size of the material can be systematically adjusted, and that the functional groups are easily modified. High porosity and special functional pore surfaces are widely used in the fields of gas storage and separation, optics, electromagnetic materials, chemical sensing, catalysis and biomedicine. In recent years, with the rapid development of MOFs in the field of porous materials, a large number of MOFs materials with special structure have been synthesized. The development of this material has gradually changed from simple design and synthesis of MOFs materials with unique structure to the synthesis of functionally oriented MOFs materials. Through reasonable design and regulation, functional porous materials with specific properties can be obtained. The study of the structure of MOFs materials at first provided the necessary foundation for the study of MOFs functionalization, which made the functionalization of MOFs become the research hotspot in the field of porous materials. Although MOFs materials have shown excellent performance in many fields, there are still some important problems to be studied in some fields. Therefore, the design and synthesis of MOFs materials with special structure and required functions is of great significance in promoting the development of new functional porous materials. In this paper, we have designed and synthesized an organic ligands of 4 ~ 4- bipyridine and trianiline under solvothermal conditions. The porous hexagonal cobalt cluster MOF material constructed by oxygen-containing organic ligands has a traditional three-dimensional pillared structure, larger carbon nanotube channels, and a topological structure of 38-connected network structure, and its topological structure is characterized by a 38-connected network structure, which is characterized by a DEF Co6-MOFN Co_6-MOF = a trianiline, a trianiline, a bpyridine-4444-bipyridyl, a conventional three-dimensional pillared structure, a large carbon nanotube pore, and a topological structure characterized by a 38-connected network structure. The topological symbol is 4 ~ (4) ~ 3 ~ 2 ~ (6) ~ (6) ~ (6) ~ (6) ~ (18. 8) ~ (4). It is precisely because the MOF material has a pillared structure, a large pore channel and a high specific surface area, it has a good adsorption on NSP _ 2 and CO_2. In addition, the MOF material exhibits good acid resistance, alkali resistance and stable presence in air. Due to the existence of the unique hexanuclear cobalt cluster structure in the MOF material, it exhibits good antiferromagnetism. The remarkable characteristic of this MOF material is that the special connection between hexanuclear cobalt clusters and ligands makes it exhibit good catalytic performance in photocatalytic CO_2 reduction. In this paper, the photocatalytic properties of the MOF material for CO_2 reduction were studied, and the catalytic mechanism was inferred and verified by theoretical calculation.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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