Recent progress of advanced Co3O4-based materials for electrocatalytic oxygen evolution reaction in acid: from rational screening to efficient design

Electrocatalytic water splitting is an efficient way to produce high-purity hydrogen. However, the oxygen evolution reaction (OER) exhibits sluggish kinetics, severely hindering large-scale hydrogen production. The development of OER electrocatalysts with high activity, excellent durability, and cost-effectiveness, especially under high working potential and corrosive acidic conditions, plays a crucial role in the electrochemical process. Co3O4-based materials have emerged as promising candidates for replacing noble iridium (Ir)- and ruthenium (Ru)-based materials due to their flexible electronic structure, high activity, and long-term stability toward OER in acid. In this review, the recent progress of Co3O4-based electrocatalytic materials for the acidic OER is first presented, with particular reference to the catalytic mechanism and guidelines for the design principles from both experimental and theoretical perspectives. Afterward, emerging strategies are outlined to improve the catalytic performance of Co3O4-based acidic OER catalysts, including phase engineering, component regulation with doping, composite with carbon-based materials, and multi-phase hybridization. Then, some challenges and future directions in developing high-performance Co3O4-based electrocatalysts for OER in acid are proposed.