Effect of ZIF-67-derived Co3O4 on the activity of CNTs/ NiCo2O4 nanocomposite for methanol oxidation reaction

Abstract

The development of a hybrid electrocatalyst with multi-active sites that enhances the efficiency of the anodic reaction in the direct methanol fuel cells (DMFCs), is an important topic. Zeolite imidazole frameworks (ZIFs) and transition metal oxides exhibit promising performance in this regard. Herein, novel nanocomposites of nickel cobaltite (NiCo 2 O 4 ), carbon nanotubes (CNTs), and ZIF-67-derived Co 3 O 4 rhombic dodecahedron nanoparticles were prepared using the hydrothermal process followed by the pyrolysis method. The electro-catalytic activity and stability of the prepared electrodes toward methanol electro-oxidation were investigated in basic medium. The results show that ZIF-67/CNTs/NiCo 2 O 4 /NF is the most promising nanocomposite for methanol electro-oxidation with a delivered catalytic current density of 160 mA cm −2 at a scan rate of 40 mV‧s −1 . The synergistic effect of combining CNTs with NiCo 2 O 4 and ZIF-67 is the reason for the highly electro-catalytic activity of ZIF-67/CNT/NiCo 2 O 4 /NF. This new structure and composition introduce a promising avenue for the development of electrocatalysts for methanol electro-oxidation. • Novel nanocomposites of nickel cobaltite, CNTs, and ZIF-67-derived Co 3 O 4 were prepared. • The electro-catalytic activity towards methanol electro-oxidation was investigated. • ZIF-67/CNT/NiCo 2 O 4 /NF shows a current density of 160 mA cm −2 at a scan rate of 40 mV‧s −1 . • A synergistic effect is the reason for the high catalytic activity of ZIF-67/CNT/NiCo 2 O 4 /NF.