Highly Active and Easily Fabricated NiCo2O4 Nanoflowers for Enhanced Methanol Oxidation

Abstract

Metal oxides with tailored nanomorphology represent a powerful tool to improve the electrocatalytic activity. Herein NiCo2O4 nanoflowers were synthesized via facile microwave method. NiCo2O4 nanoflowers were characterized by scanning and transmission electron microscopy, X‐ray diffraction (XRD), Raman spectroscopy, N2 gas adsorption/desorption, and X‐ray photoelectron spectroscopy (XPS). Through comparing NiCo2O4 nanoparticle vs nanoflowers morphology, NiCo2O4 nanoflowers have a superior mass and specific electroactivity towards oxygen evolution reaction (OER) by achieving a current density of 10 mA/cm2 at an overpotential of only 280 mV in 1M KOH electrolyte. Moreover, NiCo2O4 nanoflowers display superior performance for methanol electrooxidation in fuel cells by achieving 200 A/g and recovers 92.3 % of the original activity through the addition of new (1M KOH + 0.5M methanol) electrolyte after 500 cycles.