Free standing growth of MnCo2O4 nanoflakes as an electrocatalyst for methanol electro-oxidation

Abstract

Binary metal oxides are emerging as a new class of electro-catalyst for the direct methanol fuel cell (DMFC). In this report, porous MnCo₂O₄ nanoflakes were directly grown on a nickel foam (NF) substrate using a simple and template-free electrodeposition method followed by annealing treatment. The MnCo₂O₄/NF electrode showed an initial current density of 96 A g⁻¹ (at a scan rate of 10 mV s⁻¹) with a retention of 90% after 1000 cyclic voltammetry cycles. The binder and carbon-free MnCo₂O₄/NF electrode showed high electrocatalytic activity, lower overpotential and long-term stability in methanol electro-oxidation compared to a Co₃O₄/NF electrode. The superior electrochemical performance is mainly attributed to the unique porous structure directly grown on the NF substrate, offering faster ion/electron transfer. According to our investigation, it can be concluded that the present simple and low cost electrodeposition technique can be used for the synthesis of other metal oxides for different energy storage and conversion applications.