Shape-Selective Growth of Bimetallic Nanostructures

Abstract

Bimetallic Pt-based and Au/Ag nanostructures nanocrystals have attracted tremendous attention in recent years because they have shown unique catalytic and optical properties. In this regard, we firstly tailored the galvanic replacement reaction (GRR) for the synthesis of Pt/Ag bimetallic hollow nanostructures with controlled number of voids, such as hollow boxes, dimers, multimers, and popcorns. GRR was also employed with seed-mediated growth method to fabricate Au/Ag sandwich nanostructures with interior gaps, in which SERS probe molecules were embedded. Such sandwich nanostructures are promising SERS-active substrates. In addition, the seed-mediated growth method was applied to control the deposition of Ag on Au bipyramids. By tuning the reaction kinetics, Au@Ag core-shell nanorods fully terminated with {110} end facets were obtained for the first time. The above mentioned series of shape-controlled syntheses of Pt/Ag and Au/Ag bimetallic nanostructures should advance our current understanding on the growth mechanism of bimetallic nanostructures.