The design of cost-effective,highly active catalysts for hydrogen energy production is a vital element in the societal pursuit of sustainable energy.Water electrolysis is one of the most convenient processes to produce high purity hydrogen.Cobalt-based catalysts are well-known electrocatalysts for oxygen evolution reaction (OER).In this article,all these merits indicate that the present cobalt nanocomposite is a promising electrocatalyst for OER.C-Co3O4-nanorods catalyst with nanorod structure was synthesized by hydrothermal treatment of CoCl26H2O/dextrose/urea mixture at 180 ℃ for 18 h and then calcined at 400 ℃ for 3.5 h.The role of dextrose percentage in solution to achieve the uniform coating of carbon on the surface of Co3O4-nanorods has been demonstrated.The prepared materials were characterized by X-ray diffraction (XRD),X-ray photoelectron spectrum (XPS),field emission scanning electron microscopy (FE-SEM),high-resolution transmission electron microscopy (HR-TEM),and Brunauer-Emmett-Teller instrument (BET).Due to its unique morphology,the C-Co3O4-nanorods catalyst exhibited better activity than Co3O4-microplates catalyst for OER in 1 M KOH aqueous solution.The results showed a highly efficient,scalable,and low-cost method for developing highly active and stable OER electrocatalysts in alkaline solution.