Porous single-crystalline AuPt@Pt bimetallic nanocrystals with high mass electrocatalytic activities

Abstract

Au–Pt bimetallic structures can effectively improve the activity and stability of catalysts in several fuel cell related electrochemical reactions. However, most of the methods for the preparation of Au–Pt nanocrystals (NCs) with core–shell structures are step-wise syntheses, which are adverse for reducing the production costs and the scale-up process. This paper describes a one-pot synthesis of rhombic dodecahedral AuPt@Pt bimetallic nanocrystals with dendritic branches. The dendritic branches on the surfaces were grown through oriented attachment and the whole particle exhibited a single-crystal structure. The thickness of the dendritic Pt shell can be controlled by tuning the introduced Pt precursor. With the Au-enhancement effect arising from the Au–Pt bimetallic core and high atom utilization efficiency provided by the porous structure, the AuPt@Pt bimetallic NCs exhibited greatly enhanced electrocatalytic properties (e.g. oxygen reduction reaction and formic acid oxidation) than those of the commercial Pt/C catalyst.