Synthesis of Magnetite Nanoparticles and Its Application As Electrode Material for the Electrochemical Oxidation of Methanol

In this study, magnetite (Fe 3 O 4 ) nanoparticles were synthesized by a simple and facile chemical co-precipitation method at ambient laboratory conditions. The synthesized Fe 3 O 4 nanostructures were characterized for their morphology, size, crystalline structure and component analysis using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, x-ray diffraction and electron dispersive x-ray spectroscopy. The Fe 3 O 4 nanoparticles showed semi-spherical geometry with an average particle diameter up to 14 nm. The catalytic properties of Fe 3 O 4 nanoparticles were evaluated for electrochemical oxidation of methanol. For this purpose, the magnetite NPs were coated on the surface of an indium tin oxide (ITO) electrode and used as a working electrode in the electrochemical oxidation of methanol. The effect of potential scan rate, the concentration of methanol, the volume of electrolyte and catalyst (Fe 3 O 4 NPs) deposition volume was studied to get high peak current densities for methanol oxidation. The stability and selectivity of the fabricated electrode (Fe 3 O 4 /ITO) were also assessed during the electrochemical process. This study revealed that the Fe 3 O 4 /ITO electrode was highly stable and selective towards methanol electrochemical oxidation in basic (KOH) media. Bare ITO and Fe 3 O 4 NPs modified glassy (Fe 3 O 4 /GCE) electrodes were also tested in the electro-oxidation study of methanol, but their peak current density responses were very low as compared to the Fe 3 O 4 /ITO electrode, which showed high electrocatalytic activity towards methanol oxidation under similar conditions. We hope that Fe 3 O 4 nanoparticles (NPs) will be an alternative for methanol oxidation as compared to the expensive noble metals (Pt, Au, and Pd) for energy generation processes. Graphical Abstract