Rhodium Nanosheets–Reduced Graphene Oxide Hybrids: A Highly Active Platinum-Alternative Electrocatalyst for the Methanol Oxidation Reaction in Alkaline Media

For the large-scale commercialization of direct methanol fuel cells, developing Pt-alternative anode electrocatalysts with low cost and high activity plays an important role. In this work, a one-pot hydrothermal method has been developed for the direct synthesis of the Rh nanosheets (Rh-NSs) on reduced graphene oxide (RGO). The newly prepared Rh-NSs/RGO hybrids have great electrocatalytic activity for the methanol oxidation reaction (MOR) in alkaline media, much better than single-component Rh nanoparticles (Rh-NPs) and Rh nanoparticles/RGO (Rh-NPs/RGO) hybrids, originating from the two-dimensional structure of Rh nanosheets and excellent physical/chemical property of the RGO. Very importantly, cyclic voltammetry (CV) measurements show the onset oxidation potential of the MOR at the Rh-NSs/RGO hybrids negatively shift ca. 120 mV compared to the commercial Pt/C electrocatalyst. Meanwhile, CV measurements show that the MOR current at the Rh-NSs/RGO hybrids is 3.6 times bigger than that at the commercial Pt/C electrocatalyst at 0.61 V potential. Additionally, chronoamperometry measurement shows the Rh-NSs/RGO hybrids have excellent stability for the MOR. These electrochemical data demonstrate that the Rh-NSs/RGO hybrids are a highly promising Pt-alternative anode electrocatalyst for the MOR in alkaline media.