Size-controllable synthesis of ultrafine PtNi nanoparticles uniformly deposited on reduced graphene oxide as advanced anode catalysts for methanol oxidation

A one-pot thermos-reduction strategy is developed to prepare ultrafine PtNi alloy nanoparticles (NPs), which are uniformly deposited onto reduced graphene oxides (RGOs) in the presence of polyvinylpyrrolidone (PVP). The size of PtNi NPs on RGOs can be tuned from 2.5 to 5.4 nm, after Ni was alloyed with Pt by Pt/Ni atomic ratio increased from 2:1 to 5:1. The electrochemical investigation demonstrates that Ni modification can promote the electrocatalytic activity of Pt catalysts on oxidation of methanol with a mass current density up to 1065 mA mg−1, which is 2.65 times that of Pt catalysts without Ni modification, and comparable to and even better than those of the Pt-based catalysts reported recently.