Core-shell gold/silver nanoparticles: Synthesis and optical properties
Core-shell gold/silver nanoparticles: Synthesis and optical properties
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DOI：
10.1016/j.jcis.2012.09.057
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发表时间：
2013-02-15
影响因子：
9.9
通讯作者：
Goia, Dan V.
中科院分区：
文献类型：
--
作者：
Lu, Lu;Burkey, Gwendolyn;Goia, Dan V.
采用两步法制备了高度分散的金银核壳纳米粒子。用L-抗坏血酸快速还原HAuCl4，首次得到平均直径约30 nm的无稳定剂金核粒子。随后，通过减少在金溶胶中添加的受控量的硝酸银，获得了厚度可变的薄的连续银壳。随着沉积银量的增加，金的等离子体激元带逐渐蓝移，最终出现银的峰值特征。当银含量超过60wt.%时，记录到一个强烈且清晰的银吸收带。结果表明，金前驱体溶液中氯离子的浓度对双金属溶胶的稳定性和沉积银壳的结构起着至关重要的作用。(C)2012 Elsevier Inc.保留所有权利。
Highly dispersed gold-silver core-shell nanoparticles were synthesized in a two-step process. The stabilizer-free gold core particles with an average diameter of similar to 30 nm were first precipitated by rapid reduction of HAuCl4 with L-ascorbic acid. Thin continuous silver shells of variable thickness were subsequently obtained by reducing controlled amounts of silver nitrate added in the gold sol. The plasmon band of gold gradually blue-shifted and a peak characteristic for silver eventually emerged as the amount of deposited silver increased. A strong and well-defined silver absorption band was recorded when the Ag content exceeded 60 wt.%. It is shown that the concentration of Cl- ions in the gold precursor solution plays a critical role in the stability of the bi-metallic sol and the structure of the deposited silver shell. (c) 2012 Elsevier Inc. All rights reserved.