Facile Synthesis of Cobalt Oxide Nanoparticles by Thermal Decomposition of Cobalt(II) Carboxamide Complexes: Application as Oxygen Evolution Reaction Electrocatalyst in Alkaline Water Electrolysis

Cobalt oxide nanoparticles, Co3O4 (1) and Co3O4 (2), have been synthesized by thermal decomposition of [CoII(bqbenzo)] and [CoII(bqb)], respectively. The morphology of these oxides is influenced by the difference in the structure of bqbenzo2− {3,4-bis(2-quinolinecarboxamido) benzophenone and, bqb2− {bis(2-quinolinecarboxamido)-1,2-benzen}, only differing in a benzoyl substituent. The products were characterized by XRD, FE-SEM, and FT-IR spectroscopy. The catalytic activity of the oxides was examined in oxygen evolution reaction (OER) by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The Co3O4 oxides (1 and 2) exhibited higher catalytic activity compared to 10 wt% Pt/C in terms of obtained current density at 0.8 V; ∼23.3 versus 6.1 mA cm−2, respectively. However, the aging tests of the two oxides in OER revealed that Co3O4 (1) is more stable than Co3O4 (2). These results demonstrated that the Co3O4 (1) has a superior performance which can be employed in the alkaline water electrolyzer anode.