Activating the Basal Planes and Oxidized Oxygens in Layer‐Structured Na0.6CoO2 for Boosted OER Activity

• Published in: Advanced science Vol. 11; no. 4
• Main Authors: Xiong, Bing, Fu, Tingxin, Huang, Qiuping, Wang, Jianlin, Cui, Zhangzhang, Fu, Zhengping, Lu, Yalin
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.01.2024; Wiley
• Subjects: active areas; layered oxides; Morphology; oxidized oxygens; Oxygen; oxygen evolution reaction; Scanning electron microscopy; Voltammetry
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202305959

With the CoO2 slabs consisting of Co4O4 cubane structure, layered NaxCoO2 are considered promising candidates for oxygen evolution reaction (OER) in alkaline media given their earth‐abundant and structural advantages. However, due to the strong adsorption of intermediates on the large basal planes, NaxCoO2 cannot meet the activity demands. Here, a novel one‐pot synthesis strategy is proposed to realize the high solubility of iron in NaxCoO2 in an air atmosphere. The optimist Na0.6Co0.9Fe0.1O2 exhibits enhanced OER activity compared to their pristine and other reported Fe‐doped NaxCoO2 counterparts. Such an enhancement is mainly ascribed to the abundant active sites on the activated basal planes and the participation of oxidized oxygen as active sites independently, which breaks the scaling relationship limit in the OER process. This work is expected to contribute to the understanding of the modification mechanism of Fe‐doped cobalt‐based oxides and the exploitation of layer‐structured oxides for energy application. The incorporation of Fe into CoO2 slabs significantly improve the oxygen evolution reaction (OER) activity of layered Na0.6CoO2. The enhancement is mainly ascribed to the enriched active sites on the activated basal planes and the participation of oxidized oxygen as active sites independently, which breaks the scaling relationship limit in the OER process.