Bimetallic nanodendrites via selective overgrowth of noble metals on multiply twinned Au seeds

Abstract

Mastery over the morphology of nanomaterials usually enables control of their properties and enhancement of their usefulness for a given application. Herein, we present a general approach, which is based on the preferential nucleation and growth of noble metals on the active twins of Au seed particles, for the fabrication of bimetallic Au-noble metal nanoparticles with dendritic morphologies. This strategy involves the synthesis of multiply twinned Au seeds and the subsequent reduction of other noble metal precursors in oleylamine at elevated temperature. In comparison with commercial Pt/C catalysts, the bimetallic Au-Pt nanodendrites display superior catalytic activity towards methanol oxidation due to the electronic interaction between the Au core and Pt branches in dendritic bimetallic particles and the abundant atomic steps, edges, and corner atoms in the Pt branches. The synthetic universality and mechanistic understanding may provide new opportunities to design and fabricate heterogeneous nanostructures with interesting physicochemical properties.