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A simple and cost-effective electrochemical method synthesized platinum nanoparticles on graphene nanosheet (PtNPs@GNS) is reported, and the Pt loading of the PtNPs@GNS can be controlled by electrodeposition. The structure and element analysis of the PtNPs@GNS have been investigated by scanning electron microscopy (SEM), Raman spectrum, X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The electrochemical measurement including electrochemical active surface area, current density, mass activity, oxidation peak potential,shows the PtNPs@GNS have more performance electrocatalytic properties for methanol oxidation reaction (MOR) compared to Vulcan XC-72 carbon (XC-72) supported PtNPs electrocatalysts. Probably, the cause which may be attributes to no aggregation of PtNPs and the well-dispersion on surface of GNS, so PtNPs@GNS show large electrochemically active surface area, highly electrocatalytic activity and stability in direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

In this study, the new electrocatalyst of platinum support on polypyrrole-functionalized graphene (GNS-PPy/PtNPs) is reported. The polypyrrole-functionalized graphene (GNS-PPy) is constructed first with graphene nanosheets (GNS) and polypyrrole (PPy) particles by constant potential deposition. And then PtNPs are deposited on the surface of GNS-PPy by cyclic voltammetry. The as-prepared GNS-PPy/PtNPs is characterized by scanning electron microscopy, energy-dispersive spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The prepared GNS-PPy/PtNPs catalyst is employed for methanol oxidation reactions. Compared with GNS/PtNPs and PPy/PtNPs, the GNS-PPy/PtNPs has higher catalytic activity (508 mA/mg), better stability, and stronger poisoning-tolerance ( I/ I = 4.18) due to high dispersion of PtNPs on large surface of GNS-PPy as well as synergic effect among the GNS, PPy particles, and PtNPs. The experimental results indicate that GNS-PPy/PtNPs may be an ideal candidate catalyst for direct methanol fuel cell. [ABSTRACT FROM AUTHOR]