NiN4/FeN4 dual sites engineered by Fe5 clusters on porous flexible carbon fibers for promoting oxygen reduction and evolution

作者：RuoJie Xu, Zhe Wang, Xiaoyan Jin, Tong Li, Zhe Lü, Zhenbei Yang, Ke‐Xin Kong, Yifan Zhang, Yong Wang, Yipu Liu, Zhijuan Pan, Seong‐Ju Hwang, Jian Fang · 发表于：Journal of Colloid and Interface Science · 年份：2025 · DOI：10.1016/j.jcis.2025.137620 · 被引用次数：5 · 研究领域：Electrocatalysts for Energy Conversion、Supercapacitor Materials and Fabrication、Nanomaterials for catalytic reactions

Dual-atom catalysts (DACs) are promising bifunctional electrocatalysts for the oxygen reduction/evolution reaction (ORR/OER) because of their tunable electronic structures and multiple types of active metal sites. However, achieving high catalyst activity and long-term durability towards both the ORR and OER when used in zinc–air batteries (ZABs) remain challenging. Herein, a flexible porous carbon fiber catalyst embedded with atomically scattered NiN 4 /FeN 4 dual sites and adjacent Fe 5 nanoclusters (NiN 4 –Fe 5 –FeN 4 @PCF) was synthesized. The optimization of the local arrangement and electronic structure of the FeN 4 /NiN 4 sites by the neighboring Fe nanoclusters conferred NiN 4 –Fe 5 –FeN 4 @PCF with excellent bifunctional ORR/OER activity and stability that were superior to those of DACs comprising only NiN 4 /FeN 4 dual sites and commercialized Pt/C and RuO 2 reference catalysts. A liquid ZAB with a NiN 4 –Fe 5 –FeN 4 @PCF cathode achieved outstanding cycling stability for over 900 h. The Fe 5 clusters effectively induced geometric structure distortion and electron redistribution of the NiN 4 and FeN 4 sites, optimizing the interactions between the FeN 4 /NiN 4 sites and oxygen intermediates; thus, the energy barriers for the potential-determining steps reduced. This study opens an emerging pathway for the synthesis of self-supporting atomic catalysts and provides in-depth insight into the synergistic effects between DACs and metal nanoclusters.