Simple synthesis of the Au-GQDs@AgPt Yolk-shell nanostructures electrocatalyst for enhancing the methanol oxidation

Abstract

Au-GQDs@AgPt Yolk-shell nanostructures with Au-GQDs yolk and AgPt alloy shell have been synthesized through a green wet chemical reduction method. In this process employed Au-GQDs as a yolk to obtain Au-GQDs@Ag nanoparticles (NPs), and then galvanic replacement reaction occurred between PtCl 6 2- and Ag to fabricate Au-GQDs@AgPt Yolk-shell nanostructures. GQDs served as a structure-directing and dispersing agent to prepare homogeneous shell. The electrocatalytic performance of the as-synthesized Au-GQDs@AgPt Yolk-shell nanostructures for methanol oxidation reaction (MOR) is studied by cyclic voltammetry (CV) and chronoamperometry (CA). The catalyst has displayed excellent specific activity (33.20 mA cm −2 ), which is approximately 7 times higher than those of commercial Pt/C. And its CO tolerance and stability for MOR are also greatly improved. The results attribute to their particular structure (Yolk-shell nanostructures), electron effect with Ag and Pt, electron transport between GQDs and AgPt shell. The present strategy can provide an environment-friendly and valuable way to fabricate multicomponent nanostructures with Yolk-shell nanostructures. Schematic illustration demonstrates the structural and compositional features of the porosity Au-GQDs@AgPt Yolk-shell nanostructures as an efficient MOR catalyst. • The unique Au-GQDs@AgPt Yolk-shell nanostructures were synthesized through a green wet chemical reducation method. • GQDs serve as a structure-directing and dispersing agent to prepare homogenous shell. • Au-GQDs@AgPt Yolk-shell enhanced catalytic performance, CO tolerance and stability for methanol oxidation reaction. • The Yolk-shell nanostructures, electron effect and electron transport are imporatant for improving catalytic performance.