Hidden Hydroxides in KOH-Grown BaNiO 3 Crystals: A Potential Link to Their Catalytic Behavior

作者：Lun Jin, Haozhe Wang, Xianghan Xu, Danrui Ni, Chen Yang, Yu‐Chieh Ku, Cheng-En Liu, Chang‐Yang Kuo, C. F. Chang, Raimundas Sereika, Wenli Bi, Weiwei Xie, R. J. Cava · 发表于：Chemistry of Materials · 年份：2023 · DOI：10.1021/acs.chemmater.3c02482 · 被引用次数：10 · 研究领域：Magnetic and transport properties of perovskites and related materials、Electronic and Structural Properties of Oxides、Perovskite Materials and Applications

The hexagonal perovskite BaNiO 3, prepared via nonceramic approaches, is known to act as a good catalyst for the oxygen evolution reaction (OER) in alkaline media. Here, we report our observation that BaNiO 3 synthesized via KOH flux growth and high-pressure ceramic synthesis with high O 2 pressure have different magnetic properties. We show that this is because the KOH flux-grown crystals made in open air are actually a hydroxide-containing form of BaNiO 3 that can be “dried” upon annealing in an O 2 flow. This work not only unveils a previously unknown aspect of the BaNiO 3 OER catalyst and offers some insights into the underlying mechanism, but also suggests that hydroxide ions may be present in other hexagonal perovskite oxides prepared in wet conditions.