PtNi Nanoparticles Loading on Sandwich-Like Hybrid Nanocarbon Support for Methanol Oxidation

Abstract

A novel electrocatalyst, PtNi-graphene/carbon dots/graphene (PtNi/GCG), for methanol oxidation was prepared onto the glassy carbon electrode (GCE). The GCG hybrid nanocarbon support with sandwich-structure was dried onto GCE surface. Then, PtNi bimetallic nanoparticles were modified loaded on the GCG hybrid nanocarbon support via electrodeposition to obtain PtNi/GCG electrocatalyst. The as-prepared PtNi/GCG electrocatalyst was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical analysis. The structure of PtNi/GCG shows that the PtNi nanoparticles were dispersed between the layered graphene. From electrochemical analysis, compared with Pt and PtNi/graphene catalysts, the as-prepared PtNi/GCG in this work has much better electrocatalytic properities towards methanol oxidation and shows better stability. The sandwich-structured electrocatalyst showed improved performance towards the methanol oxidation. The reason can be attributed to the synergistic effect between metals and the introduction of carbon dots between graphene layers. What’s more, carbon dots loading onto graphene layers effectively, which not only can increase the electrical conductivity, make available more active sites and reactive surface area, but also can enhance the dispersion of PtNi nanoparticles in the composite catalyst.