title: Effect of Ag Templates on the Formation of Au-Ag Hollow/Core-Shell Nanostructures.
abstract: Au-Ag alloy nanostructures with various shapes were synthesized using a successive reduction method in this study. By means of galvanic replacement, twined Ag nanoparticles (NPs) and single-crystalline Ag nanowires (NWs) were adopted as templates, respectively, and alloyed with the same amount of Au(+) ions. High angle annular dark field-scanning TEM (HAADF-STEM) images observed from different rotation angles confirm that Ag NPs turned into AuAg alloy rings with an Au/Ag ratio of 1. The shifts of surface plasmon resonance and chemical composition reveal the evolution of the alloy ring formation. On the other hand, single-crystalline Ag NWs became Ag@AuAg core-shell wires instead of hollow nanostructure through a process of galvanic replacement. It is proposed that in addition to the ratio of Ag templates and Au ion additives, the twin boundaries of the Ag templates were the dominating factor causing hollow alloy nanostructures.
authors.affiliation: Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 106, Taiwan.
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Tsai
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 106, Taiwan.
authors.forename: Shih-Yun
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan. samsong@nchu.edu.tw.
authors.forename: Jenn-Ming
authors.initials: JM
authors.lastname: Song
authors.affiliation: Institute for Chemical Research, Kyoto University, Kyoto, 611-0011, Japan.
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Haruta
authors.affiliation: Institute for Chemical Research, Kyoto University, Kyoto, 611-0011, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kurata
keywords: Ag@AuAg core-shell wires; AuAg alloy rings; Galvanic replacement