Surface Coalescences of Various Faceted Binary Au‐Ag Nanoparticles by Cryogenic Processes

Abstract

The surface coalescences of faceted binary Au‐Ag nanoparticles by cryogenic treatment were investigated. The binary Au‐Ag nanoparticles with various Au/Ag ratios were prepared by phase transfer method in liquid solution, and then cooled from the room temperature down to −196 °C at a very slow cooling rate. The loose surfaces of the binary Au‐Ag nanoparticles are jointed, and the clusters are surrounded with large portion of the close‐packed surfaces. The companying twining mechanism is retarded with the incorporation of Ag in Au. The jointed clusters contribute to the large red shift, especially for the mixed Au‐Ag clusters.

Keywords:

• surface coalescence
• binary Au‐Ag nanoparticle
• cryogenic process
• surface growth rate

Acknowledgments

The authors would like to thank the financial support from the national science foundation of Taiwan, Republic of China with the contract number of NSC 93‐2216‐E‐014‐002.