种子法制备单宁酸修饰的海胆状金纳米粒子及其性质研究

发布时间：2018-12-20 10:25

【摘要】：金纳米材料具有独特的光学、电学和催化等性质，是材料科学领域中最富活力的研究方向之一。近年来，金纳米材料的研究重心逐渐由单一的球型对称结构转向多元化的各项异性结构。本论文主要研究了各向异性金纳米粒子的可控合成。探讨以单宁酸为还原剂条件下，海胆状金纳米粒子的生长机制以及形貌控制因素，并研究了这些材料在在表面增强拉曼技术和催化领域中的应用。主要的工作内容包括： 1)以种子生长法制备海胆状金纳米粒子。以15nm的球型金纳米粒子作为晶核，以单宁酸作为还原剂，四氯金酸为金前体，在室温下合成各向异性金纳米粒子。系统研究了单宁酸与氯金酸的浓度比(R)以及pH对金纳米材料合成的影响。研究发现，在单宁酸与氯金酸的浓度比较低时(R2)，体系趋向于形成类球形的金纳米粒子(50nm左右)；在较高的R值下(R2)，体系趋向于形成海胆状的各向异性的金纳米粒子(70nm左右)另外，在pH3-8范围内，随着pH的升高，产物的各向异性趋于显著。当体系的pH值大于8时，金纳米粒子的各向异性程度下降，同时粒子的单分散性亦有下降。 2)研究了所合成的金纳米粒子的性质。结果表明，此条件下合成的金纳米粒子具有较好的稳定性。同时研究了材料在表面拉曼增强技术及催化领域的应用。研究发现，我们所合成的海胆状材料具有优良的表面拉曼增强活性。对对巯基苯甲酸拉曼信号增强效果优于相同尺寸的球型金纳米粒子。我们还以硼氢化钠还原对硝基苯胺的反应作为模型，，研究了材料的催化能力。
[Abstract]:Gold nanomaterials with unique optical, electrical and catalytic properties are one of the most active research fields in material science. In recent years, the center of gravity of gold nanomaterials has gradually shifted from a single spherical symmetric structure to a variety of heterosexual structures. In this paper, the controllable synthesis of anisotropic gold nanoparticles is studied. The growth mechanism and morphology control factors of sea urchin gold nanoparticles with tannic acid as reductant were investigated. The applications of these materials in surface enhanced Raman technique and catalysis were studied. The main contents are as follows: 1) Sea urchin gold nanoparticles were prepared by seed growth method. Anisotropic gold nanoparticles were synthesized at room temperature using spherical gold nanoparticles of 15nm as nucleus, tannic acid as reducing agent and tetrachloroauric acid as gold precursor. The effects of (R) and pH on the synthesis of gold nanomaterials were systematically studied. It is found that when the concentration of tannic acid and chlorau acid is low (R2), the system tends to form spherical gold nanoparticles (about 50nm). At a higher R value (R2), the system tends to form anisotropic gold nanoparticles (about 70nm) in the form of sea urchin. In addition, in the range of pH3-8, the anisotropy of the products tends to be significant with the increase of pH. When the pH value of the system is greater than 8, the anisotropy of gold nanoparticles decreases and the monodispersity of gold nanoparticles decreases. 2) the properties of the synthesized gold nanoparticles were studied. The results show that the gold nanoparticles synthesized under these conditions have good stability. At the same time, the applications of the materials in surface Raman enhancement and catalysis were studied. It is found that the synthesized sea urchin material has excellent surface Raman enhancement activity. The enhancement effect of p-mercaptobenzoic acid Raman signal is better than that of spherical gold nanoparticles of the same size. The catalytic activity of p-nitroaniline was studied by using sodium borohydride as a model for reduction of p-nitroaniline.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O614.123;TB383.1

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