Nanopartículas de Pt suportadas em nanofitas de grafeno: síntese e perspectivas de aplicação em células a combustível alimentadas por derivados da biomassa

Abstract

In this work, we reported an efficient method to convert graphene oxides nanoribbons towards Pt nanoparticles (NPs) supported on graphene nanoribbons (Pt/GNRs) in one-step synthesis. Pt/GNRs were characterized by transmission electron microscopy, scanning electron microscopy coupled to an energy dispersive X-ray spectroscopy, Raman spectroscopy, ultraviolet absorption spectroscopy, X-ray diffraction, N2-adsorption isotherms and hydrophilicity measurements. The electroactivity of Pt/GNRs NPs towards biomass-derived, namely methanol, ethanol and glycerol, was investigated through electrochemical measurements, as cyclic voltammetry and chronoamperometry. The electrochemical stability of se nanomaterials was investigated through exhaustive potential cycles, which was monitored by the decay in the current density and electrochemically active surface area. We used microscopies images to follow the degradation process. All parameters were compared to the performance of commercial Pt/C NPs. Our results revealed that Pt/GNRs do not show any significant improvement in the activity towards biomass-derived electrooxidation, but display a pronounced enhancement in the stability of the nanomaterials. Hence, our results suggest that multimetallic Pt-based NPs immobilized on GNRs are potential candidates to be used as anodes in direct alcohol fuel cells. The use of the additional metal(s) in the Pt structure might improve the activity while GNRs keep the enhanced stability.