Zhao Jianxiong, Zhang Yuwei, Ye Yike, Xu Qiucheng, Luo Songzhu, Meng Fanxu, Zhu Siyuan, Li Xiaoning, Lin Xinlong, Yu Anke, Ren Xiao, Wu Tianze, Xu Zhichuan J
School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.
Nanyang Environment and Water Research Institute (NEWRI), Interdisciplinary Graduate Programme, Nanyang Technological University, Singapore, Singapore.
Nat Commun. 2025 Jul 1;16(1):5601. doi: 10.1038/s41467-025-60728-y.
Ni(Fe) (oxy)hydroxides have long been recognized as benchmark electrocatalysts for water oxidation in alkaline media. Maximizing their activity and longevity will be vital for facilitating scalable water electrolysis. However, progress is hindered by insufficient understandings of surface Fe dynamics and by the absence of effective regulatory approach. Here we show the surface Fe dynamics beyond the immediate vicinity of Ni(Fe) oxyhydroxides on working electrode but being remotely influenced by Fe diffusion and deposition on the counter electrode. While Fe could be highly active in reversible dynamics, disruptions in this process can result in significant activity decay due to the loss or deactivation of surface Fe species. On-site regulation of Fe dynamics is inspired by pre-catalysts. [NiFe]ZnCl derives Ni(Fe) oxyhydroxide with enhanced performance due to Zn leaching and cation defects that improve Fe site accommodation. Theoretical studies suggest that Fe dissolution occurs when cation defects are lacking but shifts to Fe capture as defects increase, underscoring on-site defect manipulation to maintain the abundance of active Fe sites.
氢氧化镍（铁）长期以来一直被认为是碱性介质中析氧反应的基准电催化剂。最大化其活性和寿命对于促进可扩展的水电解至关重要。然而，由于对表面铁动力学的理解不足以及缺乏有效的调控方法，进展受到阻碍。在这里，我们展示了工作电极上氢氧化镍（铁）紧邻区域之外的表面铁动力学，但它受到对电极上铁扩散和沉积的远程影响。虽然铁在可逆动力学中可能具有高活性，但该过程的中断会由于表面铁物种的损失或失活而导致显著的活性衰减。铁动力学的原位调控受到预催化剂的启发。[镍铁]氯化锌由于锌的浸出和阳离子缺陷改善了铁位点容纳情况，从而衍生出具有增强性能的氢氧化镍（铁）。理论研究表明，当缺乏阳离子缺陷时会发生铁溶解，但随着缺陷增加会转变为铁捕获，这突出了原位缺陷操纵以维持活性铁位点的丰度。
