Synergistic regulation of different coordination shells of iron centers by sulfur and phosphorus enables efficient oxygen reduction in zinc-air batteries

• Published in: Journal of colloid and interface science 2025-02, Vol.688, p.161-171
• Main Authors: Zhao, Yi-Han, Ji, Yu-Rui, Chen, Xing-Qi, Li, Jing, Wang, Peng-Fei, Liu, Zong-Lin, Shu, Jie, Yi, Ting-Feng
• Format: Article
• Language: English
• Subjects: Coordination environment; Doping; Electronic structure; Fe[sbnd]N[sbnd]C[sbnd]S[sbnd]P; Oxygen reduction reaction; Zinc-air battery
• ISSN: 0021-9797; 1095-7103; 1095-7103
• DOI: 10.1016/j.jcis.2025.02.142

[Display omitted] •S and P synergistically regulate different coordination shells of the Fe center.•The optimized coordination environment enhances the catalytic activity.•The FeNCSP-based zinc-air battery exhibits favorable discharge performance. The modulation of the coordination environment of Fe-N4 active sites is crucial for enhancing the oxygen reduction catalytic activity of FeNC. However, comprehensively investigating the synergistic regulation of diverse coordination shells of Fe centers by various non-metallic heteroatoms poses a significant challenge. In this study, iron/sulfur/phosphorus/nitrogen-doped carbon nanotubes (FeNCSP) were synthesized through a two-step process that includes a solvothermal method followed by one-step calcination. The introduction of sulfur (S) and phosphorus (P) atoms facilitates the synergistic regulation of the first and second coordination shells of the Fe site, leading to the formation of an asymmetric coordination structure. This structural modification optimizes the electronic configuration of Fe sites and improves the adsorption energies of oxygen intermediates. Additionally, the uniformly thin-walled carbon nanotubes enhance the accessibility of active sites and improve the kinetics of the oxygen reduction reaction (ORR). The FeNCSP exhibits outstanding ORR catalytic activity, with a half-wave potential of 0.875 V, surpassing that of commercial Pt/C. Furthermore, the FeNCSPbased zinc-air battery (ZAB) shows a remarkable peak power density (158 mW cm−2) and a high discharge specific capacity (817 mAh g−1 Zn@50 mA cm−2). This work elucidates the structure-activity relationship between the coordination environment of Fe-N4 active sites and ORR catalytic performance, providing a novel perspective for designing and optimizing transition metal-nitrogen-carbon catalysts.