Size-Dependent Electrochemistry and Electrocatalysis at Single Au@Pt Bimetallic Nanoparticles

Single nanoparticle electrochemistry has attracted much attention because it can reveal the details of the electrochemical/electrocatalytic reaction mechanism that is always masked in ensemble-averaged measurements. In this work, single Au@Pt bimetallic nanoparticles have been prepared on the surface of nanoelectrodes using surface modification and copper underpotential deposition/Pt replacement reaction. The prepared single Au@Pt nanoparticle modified nanoelectrodes (Au@Pt SNPEs) show size-dependent voltammetry and electron-transfer rate, and the electrocatalytic activity toward the formic acid oxidation (FAO) is also related to the Au@Pt bimetallic nanoparticle size. This work can help us deeply understand the electrochemistry/electrocatalysis at a single nanoparticle level, which are important in fundamental research, energy-related field, and sensing/biosensing.