Tailoring Nanocrystalline/Amorphous Interfaces to Enhance Oxygen Evolution Reaction Performance for FeNi‐Based Alloy Fibers
Bo Li, Sida Jiang, Qiang Fu, Ran Wang, Weizhi Xu, Junxiang Chen, Chen Liu, Ping Xu, Xianjie Wang, Jianhua Li, Hongbo Fan, Juntao Huo, Jianfei Sun, Zhiliang Ning, Bo Song
Abstract
Abstract Efficient oxygen evolution reaction (OER) electrocatalysts play a pivotal role in water electrolysis, notably for industrial high current densities (>1000 mA cm −2 ). Crystalline/amorphous heterostructure interfaces have proven to be advantageous for enhancing the OER activities of electrocatalytic materials. However, the constructing and tailoring for crystalline/amorphous interfaces still remain a great challenge due to the destruction of active substrates by intricate post‐treatment. Here, a strategy to tailor nanocrystalline/amorphous (N/A) interface and optimize the electrocatalytic performance of as‐cast N/A alloys by adjusting the size of nanocrystals is proposed. The N/A alloy fibers obtained based on this strategy exhibit superior OER performance with an overpotential of 227 mV (@10 mA cm −2 ), maintaining stability for over 1000, 600, and 240 h under high current densities of 500, 1000, and 1800 mA cm −2 , respectively. Theoretical calculations and material characterizations reveal that N/A interfaces, facilitated by appropriately sized nanocrystals possessing a loose atomic arrangement, favorable surface electronic structure, advantageous local coordination, and optimal O‐contained intermediate adsorption, can yield abundant active sites without compromising stability. This study not only provides a deeper understanding of the tailoring mechanism of N/A interfaces but also offers a new design perspective for the development of cost‐effective, industrial‐grade electrocatalysts.