Bimetallic Ag–hollow Pt heterodimers via inside-out migration of Ag in core–shell Ag–Pt nanoparticles at elevated temperature

Abstract

Bimetallic heterodimers often exhibit unique and superior properties different from each of the constituent materials due to the synergistic effect between the two component metals. Herein, we present the synthesis of bimetallic heterodimers consisting of Ag and hollow structured Pt nanoparticles (Ag–hPt) through a structural transformation at elevated temperature. In this strategy, core–shell Ag–Pt nanoparticles are first prepared and, subsequently, converted into bimetallic Ag–hPt heterodimers via the inside-out migration of Ag in core–shell Ag–Pt nanoparticles. The heat treatment at elevated temperature is employed to promote the inside-out diffusion of Ag from the core region of the core–shell nanoparticles. The resulting bimetallic Ag–hPt heterodimers display significantly different optical and catalytic properties from their core–shell Ag–Pt nanoparticle precursors. The synthetic technique and mechanistic understanding may provide new opportunities to design and fabricate heterogeneous nanostructures with interesting physicochemical properties.