Facile synthesis of ionic-liquid functionalized graphite oxide nanosheets for a highly efficient fuel cell

Abstract

Graphite oxide nanosheets (GONs) functionalized by 1-butyl-3-methylimidazolium ([BMI]), which was named as [BMI]-GONs, were synthesized by a “green” electrochemical method with the assistance of an ionic liquid ([BMI][CF₃CO₂]). Notably, based on the ordered sandwich structures and modified properties of the GONs, in the present synthetic process, Pt nanoparticles can easily assemble on the surfaces and margins of the [BMI]-GONs. Therefore, a novel [BMI]-GONs/Pt nanohybrid (porous Pt nanospheres with diameters ranging from 50 to 100 nm, which were composed of the Pt nanocrystals with the diameter ranging from 1 to 5 nm, evenly dispersed on the GONs surface) have been synthesized successfully. Furthermore, [BMI]-GONs/Pt nanohybrids were demonstrated to exhibit a much better electro-catalytic activity (the current density is 41.8 mA mg⁻¹) and stability (the current density still remains 78.9% after one thousand cycles under a scan rate at 50 mV s⁻¹) toward methanol electro-oxidation, as well as a much better resistance to toxic CO (the ratio of If/Ib is 1.97).