A tetranuclear cobalt complex [CoV4III (L')(6)] was synthesized by the direct reaction of cobalt(II) acetate with a N2S2 Schiff base ligand H2L containing a disulfide bond under aerobic conditions {H2L = 2,2'-bis(2-hydroxynaphthyliminobenzyl)disulfide}. The X-ray crystal structure of [Co-4(III)(L')(6)] indicates reductive disulfide bond scission of H2L upon reaction with Co2+ to give [L'](2-). Furthermore, cobalt oxide nanoparticles of about 30 nm size were synthesized by thermal decomposition of [Co-4(III)(L')(6)] as a precursor. The Co3O4 nanoparticles were characterized by XRD, FE-SEM, TEM, and FT-IR spectroscopy. The electrocatalytic activity of the resulting oxide was examined in oxygen evolution reaction (OER) by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) in 1.0 mol L-1 KOH. The NPs displays efficient electrocatalytic activity for oxygen evolution reaction with a current density of 10.0 mA cm(-2) at 1.65 V, good onset potential of 1.52 V vs. RHE and small Tafel slope of 44 mV dec(-1). (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.