Highly dispersed Ag nanoparticles on nanosheets of reduced graphene oxide for oxygen reduction reaction in alkaline media

Uniformly dispersed Ag nanoparticles were successfully obtained on reduced graphene oxide (RGO) through the simultaneous reduction of Ag and graphene oxide (GO) without surfactant by controlling growth of Ag nanoparticles at low temperatures. Using this method, even a high metal loading of 60 wt.% Ag with a mean diameter of less than 10 nm could be achieved over the RGO sheets. The oxygen reduction reaction activity was investigated using an RGO-supported Ag catalyst (Ag/RGO) in a 0.1 M NaOH solution, and the kinetic parameters were determined using the rotating disk electrode (RDE) technique. For comparison, a commercial carbon-supported Ag catalyst (Ag/C) was investigated under identical experimental conditions.

► The Ag/RGO is prepared via a simple surfactant-free synthetic process at low temperatures. ► The Ag/RGO demonstrates high activity compared to conventional Ag/C with respect to oxygen reduction. ► The activity enhancement arose from the high active surface area of the Ag/RGO.