▎ 摘 要
Platinum (Pt) nanoparticles of varying average diameters decorated on exfoliated reduced graphene oxide (Pt/rGO) of various functionalities have been synthesized by monitoring the temperature of co-reduction of Pt-IV and GO. The as-synthesized composites are characterized by X-ray diffraction, spectroscopic, thermo gravimetric and microscopic studies. The excellent catalytic capability of the composites for methanol oxidation reaction (MOR) is found to be synergistic in reference to single components, Pt and rGO and might be used in high efficient, less emissive, cost-effective direct methanol fuel cell operated in alkali. The poison tolerance capability of the electrodes as measured by the ratio of forward and backward peak currents due to MOR is found to be relatively high in respect to similar data in the literature and increases with the increase of defect concentration as evaluated from Raman spectroscopic study, on rising the temperature of synthesis of the catalyst. The forward peak current density of the electrode made with Pt/rGO composite synthesized at 40 degrees C is greater by 5.6 and 287 times than these for pure Pt and rGO based electrodes. The electrode exhibits the best catalytic activity due to presence of the lowest but sufficient defect sites, especially for formation of sp(2)-C-OH groups on the rGO surface in the vicinity of the poisoned Pt-surface and lowest average diameter (7.41 nm) of dispersed Pt nanoparticles.