Oxygen evolution reaction (OER) is a half-reaction that occurs at the anode during water electrolysis, and owing to its slow kinetics, it is the rate-limiting step in the process. Alloying with transition metal and combining with transition metal oxide supports are effective methods for modifying the electronic structure of noble metal catalysts and improving their catalytic properties. In this study, we synthesized IrCu/Co3O4 hybrid nanostructures by attaching IrCu alloy nanoparticles onto Co3O4 nanosheets. The electron transfer from Ir to Co altered the electronic structure of IrCu and became a crucial factor for the enhanced catalytic activity of the IrCu/Co3O4 hybrid nanostructure in the OER reaction. Additionally, the hybrid nanostructure demonstrated excellent catalytic stability under both alkaline and acidic conditions (135 and 60 h at 10 mA cm-2, respectively) due to its combination with Co3O4 nanosheets. The present work paves a new approach for the design and construction of efficient pH-universal electrocatalysts for OER.