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

RuoJie Xu; Zhe Wang; Xiaoyan Jin; Tong Li; Zhe Lu; Zhenbei Yang; Kexin Kong; Yifan Zhang; Yong Wang; Yipu Liu; Zhijuan Pan; Seong-Ju Hwang; Jian Fang

doi:10.1016/j.jcis.2025.137620

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

J Colloid Interface Sci. 2025 Sep:693:137620. doi: 10.1016/j.jcis.2025.137620. Epub 2025 Apr 16.

Authors

RuoJie Xu¹, Zhe Wang², Xiaoyan Jin³, Tong Li⁴, Zhe Lu¹, Zhenbei Yang¹, Kexin Kong¹, Yifan Zhang¹, Yong Wang⁵, Yipu Liu⁶, Zhijuan Pan¹, Seong-Ju Hwang⁷, Jian Fang⁸

Affiliations

¹ College of Textile and Clothing Engineering, National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, PR China.
² College of Textile and Clothing Engineering, National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, PR China. Electronic address: zhewang1119@suda.edu.cn.
³ Department of Applied Chemistry, University of Seoul, Seoul 02504, Republic of Korea.
⁴ State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, PR China.
⁵ School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 Singapore.
⁶ State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, PR China. Electronic address: liuyp@hainanu.edu.cn.
⁷ Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea. Electronic address: hwangsju@yonsei.ac.kr.
⁸ College of Textile and Clothing Engineering, National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, PR China. Electronic address: jian.fang@suda.edu.cn.

PMID: 40252579
DOI: 10.1016/j.jcis.2025.137620

Abstract

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 NiN₄/FeN₄ dual sites and adjacent Fe₅ nanoclusters (NiN₄-Fe₅-FeN₄@PCF) was synthesized. The optimization of the local arrangement and electronic structure of the FeN₄/NiN₄ sites by the neighboring Fe nanoclusters conferred NiN₄-Fe₅-FeN₄@PCF with excellent bifunctional ORR/OER activity and stability that were superior to those of DACs comprising only NiN₄/FeN₄ dual sites and commercialized Pt/C and RuO₂ reference catalysts. A liquid ZAB with a NiN₄-Fe₅-FeN₄@PCF cathode achieved outstanding cycling stability for over 900 h. The Fe₅ clusters effectively induced geometric structure distortion and electron redistribution of the NiN₄ and FeN₄ sites, optimizing the interactions between the FeN₄/NiN₄ 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.

Keywords: Dual-atom catalysts; Nanocluster; Oxygen reduction/evolution reaction; Porous carbon fiber; Zinc–air batteries.