<p>The cost-effective electrocatalyst for oxygen evolution is an essential substitute for the growing energy needs as well as to energy conversion devices. The CuCo₂O₄@NiMnO₃ heterostructure is prepared by a one-step solvothermal method on stainless steel strip (SSS) support and was subsequently investigated for oxygen evolution reaction (OER). The hydrothermally developed metallic oxide electrocatalysts were confirmed by using several techniques to investigate physical features. The integration of Cu and Co with bimetallic NiMnO₃ has improved charge transfer capabilities by giving rise to active sites. The potential CuCo₂O₄@NiMnO₃ electrocatalyst demonstrated an overpotential of 134 mV, a lowered Tafel slope of 26.17 mVdec⁻¹, and a high turnover frequency of 0.06 s⁻¹ at the current density of 10 mA cm⁻². In addition, it shows that OER required a low operating potential of 1.48 V in 1 M KOH solution. Besides, CuCo₂O₄@NiMnO₃ heterostructure displays optimal free energy prerequisite for reactant adsorption, a substantial electroactive surface area of 33.1 cm⁻². Furthermore, it provides exceptional stability for 100 h in regulated electrolysis experiments with no discernible decrease in OER activity. This study offers a simple synthetic method for creating effective, low-cost, and binder-free electrocatalysts.</p> Graphical Abstract <p></p>