Morphological Evolution of Single-Crystal Ag Nanospheres during the Galvanic Replacement Reaction with HAuCl 4 †

Department of Biomedical Engineering, Washington University, Saint Louis, Missouri 63130.
The Journal of Physical Chemistry C (Impact Factor: 4.77). 02/2008; 112(21):7872-7876. DOI: 10.1021/jp711662f
Source: PubMed


This paper presents a systematic study of the galvanic replacement reaction between 23.5 nm single-crystal Ag nanospheres and HAuCl(4) in an aqueous medium. We have monitored both morphological and spectral changes as the molar ratio of HAuCl(4) to Ag is increased. The replacement reaction on single-crystal Ag nanospheres results in the formation of a series of hollow and porous nanostructures composed of Au-Ag alloys. By varying the molar ratio of HAuCl(4) to Ag, we are able to control the size and density of the pores. In addition, the localized surface plasmon resonance peaks of these nanostructures can be readily tuned from 408 to 791 nm as the product becomes increasingly more hollow and porous.

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Available from: Xianmao Lu, Jan 11, 2014
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    • "As a result, the reaction product can achieve a shape which radically differs from that of the original template. Notable examples include templates which are cuboctahedrons [3] [20] [21], polyhedrons [4], multiply twinned particles (MTP) [15], and nanowires [22]. The early stages of the reaction are characterized by the preferential deposition of Au on facets having high surface energy. "
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    • "Much work has been reported by Xia et al. on shape-or morphologycontrolled nanostructures such as cubes, spheres, and other porous structures [16] [17] [18] [19] [20]. They have studied the mechanism and morphological evolution of the galvanic replacement reaction [21] [22]. Recently, we extended the replacement reaction method traditionally used to produce solid metals so that it can be used to synthesize metal oxides [23]. "
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