Enhancing the catalytic activity of Co₃O₄ electrocatalysts featuring abundant oxygen vacancies is required to enable their application in oxygen evolution reaction (OER). However, developing a harmless defect engineering strategy based on mild conditions to realize such an enhancement remains a challenge. Here, ultrathin Co₃O₄ nanosheets with abundant oxygen vacancies were prepared through a simple two-step method comprising a hydrothermal process and pre-oxidation to study the catalytic activity of the nanosheets toward OER. The ultrathin sheet structure and the Co₃O₄ nanosheets surface provide abundant active sites. The oxygen vacancy not only improves the catalyst activity, but also improves the electron transfer efficiency. These advantages make ultrathin Co₃O₄ nanosheets with abundant oxygen vacancies an excellent electrocatalyst for oxygen evolution. In an alkaline medium, ultrathin Co₃O₄ nanosheets exhibited excellent OER catalytic activity, with a small overpotential (367 mV for 10 mA/cm²) and faster reaction kinetics (65 mV/dec).Moreover, the electrocatalyst still maintained 68% of its original catalytic activity after 24 h operation. This work provides an extensive and reliable method for the preparation of low-cost and highly efficient OER electrocatalysts.

需要增强具有大量氧空位的Co ₃ O ₄电催化剂的催化活性，以使其能够用于氧释放反应（OER）中。但是，开发基于温和条件的无害缺陷工程策略以实现这种增强仍然是一个挑战。在这里，通过包括水热过程和预氧化的简单两步法制备了具有大量氧空位的超薄Co ₃ O ₄纳米片，以研究纳米片对OER的催化活性。超薄片结构和Co ₃ O ₄纳米片表面提供丰富的活性位点。氧空位不仅提高了催化剂活性，而且提高了电子转移效率。这些优点使具有大量氧空位的超薄Co ₃ O ₄纳米片成为用于氧释放的极佳电催化剂。在碱性介质中，超薄Co ₃ O ₄纳米片表现出优异的OER催化活性，具有较小的过电势（10 mA / cm ²时为367 mV ）和更快的反应动力学（65 mV / dec）。此外，电催化剂仍保持68％操作24小时后其原始催化活性的变化。这项工作为制备低成本和高效的OER电催化剂提供了广泛而可靠的方法。