Synthesis of Pt nanoparticles on electrochemically reduced graphene oxide by potentiostatic and alternate current methods

Abstract

Reduced graphene oxide (RGO) has been synthesized on Pt wires by means of a potentiodynamic method between +0.6 V and -1.4'V for 20 scans. Cyclic voltammetry characterization of the coatings showed the typical capacitative behavior of graphene. Pt nanoparticles were synthesized on Pt-RGO electrodes by means of potentiostatic methods and a comparison between different synthesis potentials (-0.16, 0, +0.2 and +0.4 V) for the same synthesis charge (mC.cm(-2)) was established. The electrodes obtained were characterized in 0.5 M H2SO4 solution to observe the characteristic oxidation and reduction processes of the Pt surface. A 0.5 M H2SO4/0.5 M CH3OH solution was used to measure the catalytic properties of the deposits against methanol oxidation. The most appropriate potential to perform the synthesis was 0 V followed by -0.16 V and +0.2 V. The morphology of the coatings varied depending on the potential applied as observed by scanning electron microscopy. Alternate current methods were also used to synthesize Pt nanoparticles and compare the results with the traditional potentiostatic method. Different frequencies were used: 0.1, 1, 10, 100, 1000 and 10000 Hz. Alternate current synthesis is more efficient than traditional potentiostatic methods, obtaining more electroactive coatings with less effective synthesis time. (C) 2014 Elsevier Inc. All rights reserved.