Electro-oxidation of Formaldehyde on A Non-Platinum Metal/RGO Nanocomposite Modified Electrode in Alkaline Solution

Since the catalysis of formaldehyde oxidation is an important subject in fuel cells and also air and water purification, in this work a novel electrocatalyst was proposed for oxidation of formaldehyde. The electrocatalyst was constructed by electro-deposition of Ni and Co nanoparticles on the reduced graphene oxide (RGO) modified carbon paste electrode (NiCoRCPE). It was characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and cyclic voltammetry. The electrocatalyst is worked by the mediation role of redox species of Ni nanoparticles in oxidation of formaldehyde. Also its ability enhanced by the synergetic effect of Ni and Co nanoparticles and the electrical properties of RGO. High current density and low over-potential for formaldehyde oxidation was obtained by the electrocatalyst. The current density is reached to 25 mAcm-2 in 200 mM of formaldehyde. The onset potential of formaldehyde oxidation at the electrocatalyst become as 0.38V and its anodic peak as 0.75V versus SCE. Also, the catalytic reaction rate constant for the electro-oxidation of formaldehyde at the modified electrode was obtained as 55.6 M-1 s-1. This high value for rate constant indicates the suitability of the proposed electrocatalyst for formaldehyde oxidation in fuel cells and purification applications.