Kinetic study of Pt nanocrystal deposition on Ag nanowires with clean surfaces via galvanic replacement
1 Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 106, Taiwan
2 Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 106, Taiwan
3 Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan
4 Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 701, Taiwan
Nanoscale Research Letters 2012, 7:245 doi:10.1186/1556-276X-7-245Published: 6 May 2012
Without using any templates or surfactants, this study develops a high-yield process to prepare vertical Ag-Pt core-shell nanowires (NWs) by thermally assisted photoreduction of Ag NWs and successive galvanic replacement between Ag and Pt ions. The clean surface of Ag nanowires allows Pt ions to reduce and deposit on it and forms a compact sheath comprising Pt nanocrystals. The core-shell structural feature of the NWs thus produced has been demonstrated via transmission electron microscopy observation and Auger electron spectroscopy elemental analysis. Kinetic analysis suggests that the deposition of Pt is an interface-controlled reaction and is dominated by the oxidative dissolution of Ag atoms. The boundaries in between Pt nanocrystals may act as microchannels for the transport of Ag ions during galvanic replacement reactions.