晶种生长法制备金银复合纳米粒子

发布时间：2018-04-01 20:16

本文选题：金银复合纳米粒子　切入点：空心金银复合纳米粒子　出处：《吉林大学》2011年硕士论文

【摘要】：金、银等贵金属纳米粒子所具有的特殊的光电和催化性质,以及良好的生物相容性,使得其在检测、催化、生物传感、医学成像及治疗等多个领域都具有重大应用价值。而具有双组分的金银复合纳米粒子由于其异于单金属纳米粒子的光学、电学、催化学性质,引起研究者们的广泛关注。本论文在水相合成中,采用晶种生长法,用抗坏血酸与硝酸银的混合溶液作为生长溶液,以柠檬酸钠作为配体的条件下,合成金银核壳纳米粒子。通过对反应条件的控制,得到高产率的、光谱范围可调的金银复合纳米粒子。金银复合纳米粒子的形貌和尺寸受还原速度以及生长速度的影响很大,由于还原剂抗坏血酸的还原能力与反应体系的pH以及抗坏血酸本身的浓度有关,所以改变体系pH或抗坏血酸浓度来研究金银复合纳米粒子生长过程。结果表明,在较高pH下,还原速度很快,银容易自成核不利于核壳结构的生长：而低pH下,反应速度太慢,不利于各向同性的生长；只有在pH适中时,银在粒子表面均匀生长成为连续壳层。另一方面,抗坏血酸的浓度过低,不能还原足量的银；而抗坏血酸过高,又有银自成核出现。通过调控pH以及抗坏血酸的浓度,制备具有不同银沉积量以及不同壳层厚度的金银复合纳米粒子。
[Abstract]:Gold, silver and other noble metal nanoparticles have special photovoltaic and catalytic properties, as well as good biocompatibility, making them in the detection, catalysis, biosensor, Many fields such as medical imaging and therapy are of great application value, and the gold and silver composite nanoparticles with two components have attracted wide attention due to their optical, electrical and catalytic properties, which are different from those of monometallic nanoparticles. In this paper, gold and silver core-shell nanoparticles were synthesized by the method of seed growth, the mixed solution of ascorbic acid and silver nitrate as growth solution and sodium citrate as ligand. Gold and silver composite nanoparticles with high yield and adjustable spectral range were obtained. The morphology and size of au / Ag composite nanoparticles are greatly affected by the reduction rate and growth rate. The reduction ability of the reductant ascorbic acid is related to the pH of the reaction system and the concentration of ascorbic acid itself. So changing the pH of the system or the concentration of ascorbic acid to study the growth process of gold and silver composite nanoparticles. The results show that at higher pH, the reduction rate is very fast, silver is easy to nucleate itself against the growth of core-shell structure, but at low pH, the reaction rate is too slow. Not conducive to isotropic growth; silver grows uniformly on the surface of particles into a continuous shell only when pH is moderate. On the other hand, ascorbic acid is too low to reduce enough silver; ascorbic acid is too high, By adjusting pH and ascorbic acid concentration, gold and silver composite nanoparticles with different silver deposition amount and different shell thickness were prepared.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TB383.1

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