铜纳米结构的可控合成及其光学性质研究
发布时间：2019-05-12 12:03
【摘要】：铜(Cu)纳米结构因其具有优异的导电、导热和延展性,且Cu价格低廉、储量丰富,在柔性透明电极、太阳能电池、催化剂等领域具有重要的应用潜能。本论文围绕Cu纳米线、Cu纳米立方体和Cu纳米四面体的制备及其光学特性开展实验和理论研究,并借助FDTD数值计算分析Cu纳米立方体的Cu纳米四面体的光吸和散射光谱,研究结果为基于Cu纳米结构的相关理论与应用研究奠定基础。本论文的具体研究内容和研究成果如下:1.基于液相还原法制备了直径均匀的五重孪晶Cu纳米线。研究溶剂热反应温度、还原剂浓度和表面包覆剂种类对Cu纳米线生长的影响。对比研究了十六胺(HDA)、十八胺(ODA)与Cu2+之间的络合物的紫外-可见(UV-Vis)吸收光谱,进而揭示出Cu纳米线的生长机制。结果表明:烷基胺与Cu2+首先形成了铜胺络合物,该络合物在高温高压条件下被还原为Cu原子;提高溶剂热反应温度或增加还原剂浓度都能够加快还原反应速率,使纳米晶体迅速成核,继而生长成为五边形双锥体结构或铅笔状纳米晶体;改变烷基胺种类,将HDA分别更换为ODA和油胺(OLA)也可以制备出Cu纳米线,但纳米线的直径较大。2.基于烷基胺的水热合成法成功制备出尺寸在一定范围内可调的Cu纳米立方体和四面体结构。通过提高络合反应温度、调整配体(单一配体或双配体)的种类及比例,获得不同形貌及结构的Cu纳米晶体,并结合动力学和热力学理论,解释了Cu纳米四面体和立方体的生长机制。实验结果表明:通过改变络合反应温度而调整铜胺络合物的浓度,可有效控制纳米晶体的形貌;降低两种配体(HDA和ODA)的比值,制备的纳米多面体的尺寸在100~600 nm范围不断增加。本工作的意义在于首次提出了Cu纳米四面体的制备方法,为以后的Cu基纳米结构的理论及实验研究奠定基础。3.利用时域有限差分(FDTD)方法模拟单个Cu纳米立方体和四面体的吸收及散射光谱,并对Cu纳米多面体在水溶液和固体粉末状态下的吸收和散射光谱加以讨论。实验测得的UV-Vis光谱是不同尺寸Cu纳米立方体和四面体的吸收光谱按照一定比率的叠加的平均效果。其中,600 nm附近的共振吸收主要来自于Cu纳米立方体,而750~950 nm宽带吸收主要是Cu纳米四面体的共振吸收。
[Abstract]:Copper (Cu) nanostructures have important application potential in flexible transparent electrodes, solar cells, catalysts and other fields because of their excellent conductivity, heat conduction and extensibility, low price and rich reserves of Cu. In this paper, the preparation and optical properties of Cu nanowires, Cu nano-cubes and Cu nano-tetrahedral are studied experimentally. the optical absorption and scattering spectra of Cu nano-tetrahedral of Cu nano-cube are analyzed by FDTD numerical calculation. The results lay a foundation for the theory and application of Cu nanostructures. The specific research contents and results of this paper are as follows: 1. Five twin Cu nanowires with uniform diameter were prepared by liquid phase reduction method. The effects of solvothermal reaction temperature, reductant concentration and surface coating agent on the growth of Cu nanowires were studied. The UV-vis (UV-Vis) absorption spectra of the complex between hexadecylamine (HDA), octadecylamine (ODA) and Cu2 were studied, and the growth mechanism of Cu nanowires was revealed. The results show that alkylamine first forms a copper amine complex with Cu2, which is reduced to Cu atom at high temperature and high pressure. Increasing the solvothermal reaction temperature or increasing the concentration of reductant can accelerate the reduction reaction rate and make the nanocrystals nucleate rapidly, and then grow into pentagonal bipyramidal or pencil-like nanocrystals. Cu nanowires can also be prepared by changing the type of alkyl amines by replacing HDA with ODA and oleoamine (OLA), respectively, but the diameter of nanowires is larger. 2. Cu nanocubes and tetrahedral structures with adjustable size were successfully prepared by hydrothermal synthesis based on alkyl amines. By increasing the temperature of complexation reaction and adjusting the type and proportion of ligands (single ligand or double ligand), Cu nanocrystals with different morphology and structure were obtained, and combined with kinetics and thermodynamic theory, The growth mechanism of Cu nano-tetrahedral and cube is explained. The experimental results show that the morphology of nanocrystals can be effectively controlled by adjusting the concentration of copper amine complex by changing the temperature of complexation reaction. By reducing the ratio of the two ligands (HDA and ODA), the size of the prepared nano-polyhedral increases in the range of 100 鈮，
本文编号：2475378
[Abstract]:Copper (Cu) nanostructures have important application potential in flexible transparent electrodes, solar cells, catalysts and other fields because of their excellent conductivity, heat conduction and extensibility, low price and rich reserves of Cu. In this paper, the preparation and optical properties of Cu nanowires, Cu nano-cubes and Cu nano-tetrahedral are studied experimentally. the optical absorption and scattering spectra of Cu nano-tetrahedral of Cu nano-cube are analyzed by FDTD numerical calculation. The results lay a foundation for the theory and application of Cu nanostructures. The specific research contents and results of this paper are as follows: 1. Five twin Cu nanowires with uniform diameter were prepared by liquid phase reduction method. The effects of solvothermal reaction temperature, reductant concentration and surface coating agent on the growth of Cu nanowires were studied. The UV-vis (UV-Vis) absorption spectra of the complex between hexadecylamine (HDA), octadecylamine (ODA) and Cu2 were studied, and the growth mechanism of Cu nanowires was revealed. The results show that alkylamine first forms a copper amine complex with Cu2, which is reduced to Cu atom at high temperature and high pressure. Increasing the solvothermal reaction temperature or increasing the concentration of reductant can accelerate the reduction reaction rate and make the nanocrystals nucleate rapidly, and then grow into pentagonal bipyramidal or pencil-like nanocrystals. Cu nanowires can also be prepared by changing the type of alkyl amines by replacing HDA with ODA and oleoamine (OLA), respectively, but the diameter of nanowires is larger. 2. Cu nanocubes and tetrahedral structures with adjustable size were successfully prepared by hydrothermal synthesis based on alkyl amines. By increasing the temperature of complexation reaction and adjusting the type and proportion of ligands (single ligand or double ligand), Cu nanocrystals with different morphology and structure were obtained, and combined with kinetics and thermodynamic theory, The growth mechanism of Cu nano-tetrahedral and cube is explained. The experimental results show that the morphology of nanocrystals can be effectively controlled by adjusting the concentration of copper amine complex by changing the temperature of complexation reaction. By reducing the ratio of the two ligands (HDA and ODA), the size of the prepared nano-polyhedral increases in the range of 100 鈮，
本文编号：2475378
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