结构新颖卟啉基复合物的制备、性能及光生电子转移研究

发布时间：2018-01-22 05:36

本文关键词： 卟啉氧化石墨烯金属氧化物非共价相互作用界面电子转移　出处：《上海应用技术大学》2016年硕士论文　论文类型：学位论文

【摘要】：卟啉及其衍生物结构特殊、易修饰、光电化学性能优越,这使得卟啉类化合物在光学、传感、染料敏化太阳能电池、分子识别和催化等领域有潜在的应用前景。本论文基于卟啉分子结构的特殊性、可调制性和优异的物理化学性能,通过非共价相互作用快速构筑多种结构可控、性能可调的卟啉基功能组装体,并进一步研究各类组装体的光电性能、光催化析氢活性、稳定性及界面光生电子转移,主要研究内容如下：通过非共价相互作用组装了三种氧化石墨烯(GO)/卟啉复合物,利用紫外光谱、荧光光谱、拉曼光谱和X射线衍射等手段表征了复合物中组分间的相互作用。利用透射电镜观察卟啉在GO表面的分布。研究了三种复合物的光电性能。研究发现,卟啉环周边的官能团对卟啉分子与GO间的结合方式和性能有重要影响。其中,5,10,15,20-四(4-羟基苯基)卟啉(THPP)和GO间存在较强的氢键及π-π相互作用,使得THPP很容易与GO作用并紧密贴合在其表面,这进一步增强了THPP与GO之间的相互作用。使GO/THPP复合物显示出比另外两种复合物更加优异的光电性能。本研究工作为通过控制卟啉分子与氧化石墨烯的结合模式调控GO/卟啉复合物的物理化学性能提供了可能。以预先通过静电相互作用铆合到GO表面的金属离子为界面连接剂,借助金属离子与5,15-二苯基-10,20-二(4-吡啶基)卟啉(DPyP)间的配位作用将DPyP与GO复合,制备了一系列金属离子桥连、DPyP柱撑的结构新颖的GO/DPyP纳米复合物。通过各种光谱、X射线衍射、氮气吸脱附曲线和透射电镜等手段对产物的结构和形貌进行表征。此外,研究了复合物的界面电子转移、光电活性和光催化制氢活性。研究结果表明：金属离子的引入可以调控GO/DPyP纳米复合物的形貌及结构,并降低了GO与DPyP之间的界面电阻,提高了光生电子的转移效率,进而提高GO/DPyP纳米复合物的光催化还原水制氢性能。本研究结果说明：在GO与卟啉界面引入金属离子是一种优化GO/卟啉纳米复合物光生电子转移路径,提高其催化活性简单而有效的方法。以周边带有四个羟基的四羟基苯基卟啉(THPP)与六面体的Cu20为主要反应物,通过搅拌回流反应制备得到了一种结构新颖的THPP/Cu2O纳米复合物。通过紫外光谱、荧光光谱等手段对比研究了THPP与Cu20的作用方式。通过电化学阻抗谱、光电性能和光催化析氢性能研究说明THPP环中心氮原子与Cu+配位,以及THPP周边羟基与Cu20表面羟基间的相互作用对于提高Cu2O/THPP复合物的性能具有协同作用。本论文研究内容的开展,为设计和开发制备方法简单、结构新颖、性能优异的卟啉基组装体提供新思路,也为解决太阳能转化为氢能或电能过程中涉及的主要关键问题一光生电子转移问题的研究提供理论指导。
[Abstract]:Porphyrins and their derivatives have special structure, easy modification and excellent photoelectrochemical properties, which make porphyrin compounds in the optical, sensing, dye sensitized solar cells. There are many potential applications in molecular recognition and catalysis. Based on the particularity of porphyrin molecular structure, modulability and excellent physical and chemical properties, various structures can be controlled rapidly by non-covalent interaction. Functional porphyrin-based assembly with adjustable properties and further study of the photoelectric properties, photocatalytic hydrogen evolution activity, stability and interface photoelectron transfer of all kinds of assemblies. The main research contents are as follows: three kinds of graphene oxide GOA / porphyrin complexes were assembled by noncovalent interaction. UV spectra and fluorescence spectra were used. Raman spectroscopy and X-ray diffraction were used to characterize the interaction between the components in the complex. The distribution of porphyrin on go surface was observed by transmission electron microscope. The photoelectric properties of the three complexes were studied. The functional groups around the porphyrin ring have an important influence on the binding mode and properties between porphyrin molecules and go. There is a strong hydrogen bond and 蟺-蟺 interaction between 20- tetra-4-hydroxyphenyl) porphyrin (THPP) and go, which makes it easy for THPP to interact with go and bind closely to its surface. This further enhances the interaction between THPP and go, and makes the GO/THPP complex exhibit better optoelectronic properties than the other two complexes. It is possible to regulate the physical and chemical properties of GO- / porphyrin complex by the binding mode of graphene. The metal ions which are riveted to go surface by electrostatic interaction in advance are used as interface binders. A series of metal ion bridges were prepared by the coordination of metal ions with 5 ~ (15) -diphenyl ~ (-10) -20 ~ (-20) -diazo _ 4-pyridyl) porphyrin (DPyP). The metal ions were synthesized by the combination of DPyP and go. Novel GO/DPyP nanocomposites with DPyP pillared structure. The structure and morphology of the products were characterized by various spectral X-ray diffraction, nitrogen adsorption and desorption curves and transmission electron microscopy. The interfacial electron transfer, photovoltaic activity and photocatalytic activity of GO/DPyP nanocomposites were studied. The results showed that the morphology and structure of GO/DPyP nanocomposites could be regulated by the introduction of metal ions. The interface resistance between go and DPyP is reduced and the transfer efficiency of photogenerated electrons is improved. Thus, the photocatalytic reduction of water for hydrogen production by GO/DPyP nanocomposites was improved. The introduction of metal ions into the interface between go and porphyrin is an optimization of photoelectron transfer path of GO- / porphyrin nanocomposites. It is a simple and effective method to improve its catalytic activity by using tetrahydroxyphenyl porphyrin (THPP) with four hydroxyl groups as the main reactant with hexahedron Cu20. A novel THPP/Cu2O nanocomposite was prepared by stirring reflux reaction. The interaction between THPP and Cu20 was studied by means of fluorescence spectroscopy. The coordination of nitrogen atom in the center of THPP ring with Cu was demonstrated by electrochemical impedance spectroscopy, photoelectric performance and photocatalytic hydrogen evolution. The interaction between the peripheral hydroxyl groups of THPP and the surface hydroxyl groups of Cu20 has synergistic effect on improving the properties of Cu2O/THPP complexes. It provides a new idea for the design and development of porphyrin-based assembly with simple preparation method, novel structure and excellent performance. It also provides theoretical guidance for the study of photoelectron transfer, which is the key problem involved in the conversion of solar energy to hydrogen or electric energy.
【学位授予单位】：上海应用技术大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O626

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