J. Mater. Sci. Technol. ›› 2025, Vol. 234: 151-163.DOI: 10.1016/j.jmst.2025.01.061

• Research Article • Previous Articles     Next Articles

In situ SO42- regulation of ZrFeCoNiAl-based high-entropy electrocatalysts to enhance O-O coupling in the oxygen evolution reaction

Bingxuan Zhaia, Yan Hea,*, Jiawen Chena, Xuemin Cuia, Leping Liub,*   

  1. aGuangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China;
    bGuangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530001, China
  • Received:2024-07-20 Revised:2024-09-11 Accepted:2025-01-18 Published:2025-11-01 Online:2025-03-27
  • Contact: *E-mail addresses: 20130017@gxu.edu.cn (Y. He), 130078@nnnu.edu.cn (L. Liu).

Abstract: To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction (OER), there is an imperative need for the development of highly efficient, cost-effective, and durable electrocatalysts. This study presents for the first time a strategy for in situ SO42- regulation of HEMs. Unlike previous studies SO42- is directly anchored to HEMs rather than formed through uncontrolled transformation or surface reconstruction. A series of novel electrocatalysts N@(ZrFeCoNiAl)Ox-SO4 [HE/NS-(0-4)] were prepared by the low-temperature NaBH4 reduction method. The content of SO42- showed an inverse volcano relationship with the OER catalytic activity, all the samples exhibit excellent OER activity and remarkable stability over 50 h. The moderate introduction of SO42--oriented HE/NS-2 forms a short-range ordered and long-range disordered structure, which stably combines high catalytic activity and excellent electrical conductivity, exhibiting LOM-dominated OER mechanism with an overpotential of 257 mV at 10 mA cm-2 and a Tafel slope of 41.86 mV dec-1. The catalytic performance of the highly crystalline HE/NS-4 electrode (291 mV @10 mA cm-2) containing a large amount of SO42- and the HE/NS-0 (340 mV @10 mA cm-2) without SO42- is both poor. SO42- as the main promoting factor, controlling the growth of HEMs morphology, structural evolution, and the adjustment of the valence state of active metal sites, playing a vital role in activating lattice oxygen and promoting O-O coupling. N as an electron donor, further improves the electronic structure of HEMs. In situ Raman spectroscopy to probe the dynamic reconstruction of HE/NS-2, anion/cation leaching facilitates self-reconstruction, and the formed metal (oxy)hydroxide is considered the active center of OER. This study pioneers a novel avenue for the controlled synthesis of oxidized anion-adsorbed HEMs and enhancing OER catalytic activity.

Key words: In situ SO42- regulation, Short-range order and long-range disorder structure, Phase evolution, Activation of lattice oxygen, Zr-HEMs, Surface reconstruction