Co3O4 nanostructures for oxygen evolution reaction: a mini review

The oxygen evolution reaction (OER) plays a critical role in electrochemical water splitting and renewable energy conversion systems. However, the sluggish reaction kinetics and high overpotential of OER remain major challenges for efficient hydrogen production. Recently, cobalt oxide (Co 3 O 4 ) nanomaterials have attracted significant attention as promising electrocatalysts due to their low cost, high catalytic activity, environmental compatibility, and rich redox chemistry. Various nanostructured morphologies including nanoparticles, nanosheets, nanowires, hollow structures, and porous architectures have demonstrated improved electrocatalytic performance by increasing active surface area and facilitating rapid charge transfer. Furthermore, composite formation with conductive carbon materials and heteroatom doping strategies have significantly enhanced the electrical conductivity and stability of Co 3 O 4 -based catalysts. This mini review summarizes recent advances in Co 3 O 4 nanomaterials for oxygen evolution reactions, focusing on synthesis methods, nanostructure engineering, electrical properties, and electrochemical performance. In addition, current challenges and future perspectives for developing highly efficient and durable Co 3 O 4 electrocatalysts are discussed.