Construction of silica-encapsulated gold-silver core-shell nanorod: Atomic facets enrichment and plasmon enhanced catalytic activity with high stability and reusability

Abstract

Although various alloys and core-shell nanoparticles with excellent plasmonic properties have been used in plasmon-enhanced catalysis, the integration of strong, tunable plasmonic properties and exceptional catalytic activities on the same nanoscale of noble metal nanoparticles remains challenging. Herein, a novel method is involved to produce highly monodisperse and uniform silica-encapsulated Au-Ag core-shell nanorod catalysts with tunable plasmonic properties. Our technique can create atomic terraces and steps, generating localized high-index facets on Ag shell by virtue of surface etching silver oxide, and these surface defects serve as active catalytic sites. It is found that the nanostructures exhibit excellent catalytic performances alongside superiorities in reusability and stability. Further investigations indicate that the plasmon-induced electromagnetic field enhancement effect also contributes to the catalytic activity of the nanostructures. The strategy will enable us to take a deep insight into the promotion of catalytic activity, stability and reusability of plasmonic nanoparticles. Keywords: Plasmon, Catalysis, Au-Ag core-shell nanorod, Terraced surface, Stability, Reusability