Perovskite oxides act as an efficient electrocatalyst, but their limited active surface area has made it challenging to enhance their electrocatalytic activity. Thus, researchers found that changing the crystalline surface to an amorphous surface having oxygen vacancy can create an enriched active zone. In this research, we adopt a top-down approach for the amorphization of the crystalline CeCoO3 nanostructure that creates crystal defects, producing materials with a higher specific surface area, potential electrocatalysis for oxygen evolution reaction (OER) and greater stability. The calculated overpotential (η) and Tafel slope for defective CoCO3 (D-CCO3) is 265 and 35.95 mV dec−1 very low as compared to the crystalline CoCO3 (C-CCO3, 384 and 76.11 mV dec−1). The electrochemical analysis also suggests that the defective CoCO3 (D-CCO) exhibited the 33.96 mF and ECSA of 849 cm2. The current research enables a valuable approach for improving and changing the material properties and electrochemical efficiency of nanoscale perovskite oxide electrocatalysts attributed to crystal defects and nitrogen doping. However, further modifications to the D-CCO structure in the near future may be employed to address other environmental challenges.