Hierarchical Porous N-doped Carbon Nanofibers Supported Fe3C/Fe Nanoparticles as Efficient Oxygen Electrocatalysts for Zn-Air Batteries

Non-precious metal nanocomposite has attracted extensive attention as an effective catalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, hierarchically porous N-doped carbon nanofibers supported Fe3C/Fe nanoparticles (denoted as Fe/N-HCNFs) have been successfully fabricated. The synthesis involved the successive steps of electrospun polyacrylonitrile (PAN) and zeolitic imidazolate framework (ZIF-8) nanofiber, surface functionalization of tannic acid (TA), coordination with ferric salt and carbonization. The obtained Fe/N-HCNFs exhibited enhanced electrocatalytic performance for both ORR and OER. Furthermore, Fe/N-HCNFs delivered a higher power density and an excellent long-term stability when applied in a constructed Zn-air battery, which illustrated its outstanding prospects for energy storage and conversion.