Yukang Xiong, Lin Lv*, Guokun Ma, Hanbin Wang, Houzhao Wan, Hao Wang*

Cite this article: Chin. J. Struct. Chem., 2025, 44(11), 100699. DOI: 10.1016/j.cjsc.2025.100699

Publication date: November 1, 2025

Keywords: Zn-air battery; Electrocatalyst; Interfacial structure; Oxygen evolution reaction; Structural evolution

ABSTRACT

Addressing the kinetic limitations of the oxygen evolution reaction (OER) is paramount for advancing rechargeable Zn-air batteries, thus it is extremely urgent to drive the development of effective and affordable electrocatalysts. This work constructed the interfacial structure of cobalt-iron alloys@ phosphates (denoted as CoFe/Co-Fe-PO) as OER catalyst through a two-step approach using water-bath and hydrothermal methods, which demonstrated significant OER activity in alkaline media, requiring a low overpotential of 271 mV to achieve 10 mA cm-2 and exhibiting a competitive Tafel slope of 65 mV dec-1, alongside sustained operational stability. The enhanced performance can be attributed to the improved electrical conductivity due to the participation of CoFe alloys and the an increased number of active sites through partial phosphorylation, which synergistically enhance charge transfer processes and accelerate OER kinetics. Moreover, dynamic structural evolution during OER process was thoroughly probed, and the results showed that alloys@ phosphates gradually evolved into phosphate radical-modified Co-Fe hydroxyoxides that act as the actual active phase. Highlighting its practical applicability, the integration of the prepared catalyst into zinc-air batteries led to markedly improved performance, thereby offering promising new strategic directions for the development of next-generation OER electrocatalysts.