Nano-crystalline Co3O4 is synthesized using solution combustion method. Characterization is done using XRD, TEM and BET surface area analysis. XRD shows pure nano-crystalline phase of Co3O4. Crystallinity of as prepared material improves by calcining the compound at 900 degrees C for 10 h while no effect is seen at 600 degrees C. TEM studies show that particles of around 50 nm size are formed at 400 degrees C. At 600 degrees C a well-defined hexagonal morphology could be seen both by TEM and SEM and the particle size is around 70 nm. However, TEM of the sample at 900 degrees C shows big agglomerates of cobalt oxide and no specific geometry could be obtained. Estimated-BET surface area for the sample calcined at 600 degrees C is 10 m(2)/g. Detailed electrochemical studies are carried out in neutral and basic electrolytes where Ag/AgCl is used as the reference electrode. It is found that Co3O4 is active for oxygen evolution reaction in basic medium as well as in neutral medium. KOH is used as the basic medium while KNO3, K2SO4 and phosphate buffer is used for neutral medium. However, it is not active for hydrogen evolution reaction in any of the medium even at -1.0 V. This is confirmed by gas analysis of the output gas in the cell by using a mass spectrometer. When compared with the buffer medium, it is observed that local pH changes in KNO3 and K2SO4 medium are possibly affecting the oxygen evolution reaction. (C) 2016 Elsevier B.V. All-rights reserved.