Hierarchical NiCo2O4/CuO-C nanocomposite derived from copper-based metal organic framework and Ni/Co hydroxides: Excellent electrocatalytic activity towards methanol oxidation

Abstract

In this work, a metal-organic framework (Cu-MOF) and two none-precious metals (Ni and Co) are used for preparation of a highly efficient electrocatalyst for methanol oxidation reaction. Nickel/cobalt hydroxides are coprecipitated on Cu-MOF in alkaline solution. The composite is then calcinated at 350 °C to obtain a carbonaceous framework and flower-like NiCo2O4 deposits (CuO-C/NiCo2O4). The obtained composite is characterized by several methods (XRD, XPS, FT-IR, SEM, TEM, and electrochemical techniques). The presence of metal oxides CuO and NiCo2O4 in the prepared electrocatalyst is confirmed by XRD and XPS methods. CuO-C/NiCo2O4 shows excellent catalytic activity towards MOR in alkaline solution (NaOH, 1 M). The electrocatalytic activity of CuO-C/NiCo2O4 is compared to stepwise composites (CuO-C/NiO, CuO/CoO, NiCo2O4) and commercial Pt/C, which confirms the superiority of the proposed catalyst in terms of current density (208.1 mA cm−2) and amperometric stability (7000 s) in methanol oxidation reaction. The observed benefits are attributed to synergistic effects between the porous conductive carbonaceous material and multi transition-metal oxides (CuO and NiCo2O4).