Liang Liwen, Miao Jiatong, Feng Xiyuan, Zhong Yunlei, Wang Wei
Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Division of Advanced Materials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China.
Micromachines (Basel). 2025 Apr 22;16(5):491. doi: 10.3390/mi16050491.
Enhancing the stability of oxygen evolution reaction (OER) catalysts is a critical challenge for realizing efficient water splitting. In this work, we introduce an innovative approach by applying an electric field during the annealing of a CoFeO/C catalyst. By controlling the electric field strength (100 mV) and treatment duration (1 h), we achieved dual optimization of the catalyst's microstructure and electronic environment, resulting in a significant improvement in catalytic stability. The experimental results demonstrate that the electric field-treated catalyst exhibits a reduced overpotential decay (only 0.8 mV) and enhanced stability (retaining 89.1% of its initial activity after 24 h) during extended OER testing. This performance significantly surpasses that of the untreated sample, which showed an overpotential decay of 1.5 mV and retained only 72.5% of its activity after 24 h. X-ray photoelectron spectroscopy (XPS) analysis confirmed that the electric field treatment promoted the formation of oxygen vacancies, substantially improved electron transfer efficiency, and optimized the local electronic environment of Co/Co and Fe/Fe, leading to a decrease in charge transfer resistance (Rct) from 58.2 Ω to 42.9 Ω. This study not only presents a novel strategy for modulating catalyst stability via electric fields but also broadens the design concepts for OER catalytic materials by establishing a structure-activity relationship between electric field strength, microstructure, and catalytic performance, ultimately providing a theoretical foundation and experimental guidance for the development of highly efficient and stable water splitting catalysts.
提高析氧反应（OER）催化剂的稳定性是实现高效水分解的关键挑战。在这项工作中，我们引入了一种创新方法，即在CoFeO/C催化剂退火过程中施加电场。通过控制电场强度（100 mV）和处理持续时间（1 h），我们实现了催化剂微观结构和电子环境的双重优化，从而显著提高了催化稳定性。实验结果表明，在长时间的OER测试中，经电场处理的催化剂表现出降低的过电位衰减（仅0.8 mV）和增强的稳定性（24 h后保留其初始活性的89.1%）。这种性能明显超过了未处理的样品，未处理样品的过电位衰减为1.5 mV，24 h后仅保留其活性的72.5%。X射线光电子能谱（XPS）分析证实，电场处理促进了氧空位的形成，大幅提高了电子转移效率，并优化了Co/Co和Fe/Fe的局部电子环境，导致电荷转移电阻（Rct）从58.2 Ω降至42.9 Ω。本研究不仅提出了一种通过电场调节催化剂稳定性的新策略，还通过建立电场强度、微观结构和催化性能之间的结构-活性关系，拓宽了OER催化材料的设计概念，最终为开发高效稳定的水分解催化剂提供了理论基础和实验指导。
