Hierarchically porous Fe/N/S/C nanospheres with high-content of Fe-Nx for enhanced ORR and Zn-air battery performance

• Published in: Green energy & environment 2023-12, Vol.8 (6), p.1693-1702
• Main Authors: Wu, Luming, Zhao, Ruge, Du, Guo, Wang, Huan, Hou, Machuan, Zhang, Wei, Sun, Pingchuan, Chen, Tiehong
• Format: Article
• Language: English
• Subjects: Hierarchically porous; High content of Fe-Nx sites; Melting perfusion; Nano-confined pyrolysis; Oxygen reduction reaction; Sulfur doping
• ISSN: 2468-0257; 2468-0257
• DOI: 10.1016/j.gee.2022.03.014

Heteroatom-doped carbon-based transition-metal single-atom catalysts (SACs) are promising electrocatalysts for oxygen reduction reaction (ORR). Herein, with the aid of hierarchically porous silica as hard template, a facile and general melting perfusion and mesopore-confined pyrolysis method was reported to prepare single-atomic Fe/N–S-doped carbon catalyst (FeNx/NC-S) with hierarchically porous structure and well-defined morphology. The FeNx/NC-S exhibited excellent ORR activity with a half-wave potential (E1/2) of 0.92 V, and a lower overpotential of 320 mV at a current density of 10 mA cm−2 for OER under alkaline condition. The remarkable electrocatalysis performance can be attributed to the hierarchically porous carbon nanospheres with S doping and high content of Fe-Nx sites (up to 3.7 wt% of Fe), resulting from the nano-confinement effect of the hierarchically porous silica spheres (NKM-5) during the pyrolysis process. The rechargeable Zn-air battery with FeNx/NC-S as a cathode catalyst demonstrated a superior power density of 194.5 mW cm−2 charge–discharge stability. This work highlights a new avenue to design advanced SACs for efficient sustainable energy storage and conversion. By a facile melting perfusion and mesopore-confined pyrolysis approach hierarchically porous Fe/N–S-doped carbon catalyst was prepared with high content single atomic Fe (3.7 wt%), and the catalyst exhibited excellent performance in ORR, OER and Zn-air battery. [Display omitted] 1.A facile melting perfusion and mesopore-confined pyrolysis approach was reported.2.Fe/N–S-doped carbon was prepared with high content single atomic Fe (3.7 wt%).3.The catalyst exhibited excellent performance in ORR, OER and Zn-air battery.4.The method is general and can be easily scaled up for different carbon materials.