Enhanced electrocatalytic activity of ion implanted rGO/PEDOT:PSS hybrid nanocomposites towards methanol electro-oxidation in direct methanol fuel cells

Abstract

Reduced graphene oxide (rGO)/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanocomposites have been synthesized via in situ polymerization technique. The synthesized nanocomposite films were implanted with Xe+ ions at different fluences of 3.3×1014, 3.3×1015 and 3.3×1016ionscm−2. The morphological, structural and elemental analyses of the implanted samples have been studied by FESEM, EDX, TEM, XRD, FTIR, Raman, RBS and XPS measurements. The electrochemical behavior of the irradiated electrodes has been investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in presence of 0.5mM ZoBell's solution containing 0.5% KCl. The electrocatalytic activities of pristine and the irradiated electrodes towards methanol oxidation have been studied by cyclic voltammetry, chronoamperometry and cyclic stability. The electrocatalytic behavior reveals that the electrode irradiated with fluence 3.3×1016ionscm−2 exhibits different CV pattern than that of the other irradiated electrodes with slightly lower oxidation potential of 0.54V and higher anodic current density of 48mAcm−2 with enhanced cyclic stability of 93% at 800th cycles. The enhanced electrocatalytic activity can be attributed to the transformation of carbonaceous layer to the graphite like clusters and change in morphology of the nanocomposite at the fluence 3.3×1016ionscm−2 as observed from FESEM and TEM images.