Reduced graphene oxide supported bimetallic Ni-Co nanoparticles composite as an electrocatalyst for oxidation of methanol

A nanocomposite for catalysis of methanol oxidation reaction was fabricated by carbon paste electrode modified with reduced graphene oxide supported bimetallic Ni-Co nanoparticles (Ni-Co/RGO/CPE). It was characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and cyclic voltammetry. The voltammetric results of the modified electrode showed a well redox activity for Ni nanoparticles which was improved by the presence of Co nanoparticles and reduced graphene oxide nanosheets. The electrochemical oxidation of methanol was investigated in alkaline media at Ni-Co/RGO/CPE. The obtained results showed that the presence of Ni-Co/RGO in the structure of electrocatalyst greatly enhance the electrocatalytic oxidation of methanol. The anodic peak potential of methanol oxidation was decreased to 0.65 V vs saturated calomel electrode and its current was greatly enhanced by Ni-Co/RGO/CPE. Also, the chronoamperometry technique was employed for obtaining the catalytic rate constant for the electmoxidation of methanol according to method of Galus as 1.05 M(-1)s(-1).