College of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China.
Key Laboratory of Core Technology of High Specific Energy Battery and Key Materials for Petroleum and Chemical Industry, College of Energy, Soochow University, Suzhou 215006, China.
Inorg Chem. 2023 Jul 3;62(26):10504-10512. doi: 10.1021/acs.inorgchem.3c01666. Epub 2023 Jun 20.
Exploring high-performance non-precious metal-based electrocatalysts for the sluggish oxygen evolution reaction (OER) process is fundamentally significant for the development of multifarious renewable energy conversion and storage systems. Oxygen vacancy (V) engineering is an effective leverage to boost the intrinsic activity of OER, but the underlying catalytic mechanism remains anfractuous. Herein, we realize the construction of oxygen vacancy-enriched porous NiO/lnO nanofibers (designated as Vo-NiO/lnO@NFs hereafter) a facile fabrication strategy for efficient oxygen evolution electrocatalysis. Theoretical calculations and experimental results uncover that, compared with the no-plasma engraving component, the presence of abundant oxygen vacancies in the Vo-NiO/lnO@NFs is conducive to modulating the electronic configuration of the catalyst, altering the adsorption of intermediates to reduce the OER overpotential and promote O* formation, upshifting the band center of metal centers near the Fermi level (), and also increasing the electrical conductivity and enhancing the OER reaction kinetics simultaneously. Raman spectra proclaim that the oxygen vacancy can render the NiO/lnO more easily reconstructible on the surface during the OER course. Therefore, the as-obtained Vo-NiO/lnO@NFs demonstrated distinguished OER activity, with an overpotential of only 230 mV at 10 mA cm and excellent stability in alkaline medium, surmounting the majority of the previously reported representative non-noble metal-based candidates. The fundamental insights gained from this work can pave a new path for the electronic structure modulation of efficient, inexpensive OER catalysts Vo engineering.
探索用于缓慢的氧气析出反应 (OER) 过程的高性能非贵金属基电催化剂对于多种可再生能源转化和存储系统的发展具有根本意义。氧空位 (V) 工程是提高 OER 本征活性的有效手段，但其中的催化机制仍然复杂。在此，我们实现了富氧空位多孔 NiO/lnO 纳米纤维 (命名为 Vo-NiO/lnO@NFs) 的构建，这是一种用于高效氧气析出电催化的简易制造策略。理论计算和实验结果揭示，与无等离子体刻蚀部分相比，Vo-NiO/lnO@NFs 中丰富的氧空位有利于调节催化剂的电子结构，改变中间体的吸附以降低 OER 过电位并促进 O*的形成，上移金属中心附近的能带中心 ()，同时提高电导率并增强 OER 反应动力学。拉曼光谱表明，氧空位可以使 NiO/lnO 在 OER 过程中更易于在表面重构。因此，所获得的 Vo-NiO/lnO@NFs 表现出出色的 OER 活性，在 10 mA cm 时仅需 230 mV 的过电位，并且在碱性介质中具有出色的稳定性，超过了大多数先前报道的具有代表性的非贵金属基候选物。这项工作获得的基本见解为高效、廉价的 OER 催化剂的电子结构调制开辟了一条新途径，即 Vo 工程。
