Highly Active and Easily Fabricated NiCo 2 O 4 Nanoflowers for Enhanced Methanol Oxidation

Abstract Metal oxides with tailored nanomorphology represent a powerful tool to improve the electrocatalytic activity. Herein NiCo 2 O 4 nanoflowers were synthesized via facile microwave method. NiCo 2 O 4 nanoflowers were characterized by scanning and transmission electron microscopy, X‐ray diffraction (XRD), Raman spectroscopy, N 2 gas adsorption/desorption, and X‐ray photoelectron spectroscopy (XPS). Through comparing NiCo 2 O 4 nanoparticle vs nanoflowers morphology, NiCo 2 O 4 nanoflowers have a superior mass and specific electroactivity towards oxygen evolution reaction (OER) by achieving a current density of 10 mA/cm 2 at an overpotential of only 280 mV in 1M KOH electrolyte. Moreover, NiCo 2 O 4 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.