Cobalt oxide (Co3O4) nanocubes were incorporated into reduced graphene oxide (RGO) using a simple single-step hydrothermal reaction for an electrocatalytic oxygen reduction reaction (ORR). The obtained nanohybrid structure of RGO@Co3O4 was adequately characterized using field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy, UV-visible spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy. The RGO@Co3O4 nanohybrid with 4 wt% of graphene oxide modified glassy carbon (GC) electrode exhibited better electrocatalytic activity in terms of the current density, overpotential and stability, compared to the other controlled modified electrodes and commercial Pt/C catalyst for the ORR in an alkaline medium. The RGO@Co3O4 nanohybrid showed good methanol tolerance for the ORR in the presence of 0.5 M methanol. (C) 2017 Elsevier Ltd. All rights reserved.