Preparation and electrochemistry of platinum nanoparticles deposited on ionic-liquid-decorated reduced graphene oxide with an enhanced methanol catalytic activity

Ionic-liquid-decorated reduced graphene oxide (IL-RGO) composites were synthesized by NaBH4 reduction. Platinum nanoparticles (Pt NPs) were then supported on the IL-RGO via a polyol process. Ionic liquid, an amphoteric ion used as an additive agent to stabilize metal nanoparticles, can also prevent the aggregation of the RGO. Compared to Pt/RGO, Pt/IL-RGO composites exhibit better electrocatalytic activity for a methanol oxidation when the mass ratio of IL to RGO is 3:1. The structural properties of the Pt nanocomposites were investigated using transmission electron microscopy, X-ray photoelectron spectroscopy, FT-IR spectroscopy, andX-ray diffraction. The results showed that the IL-RGO support could successfully introduce Pt nanoparticles with a crystallite size of about 2.5 nm. The electrochemical properties of Pt nanocomposites were confirmed using cyclic voltammetry. The electrochemical test results indicated that the electrocatalytic activities and long-term stability of the Pt/IL-RGO composites were better than those of the Pt/RGO composites. This was attributed to the increase in the electrochemical surface area after a modification with ionic liquids.