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

Abstract

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.

Hierarchical Carbon/Metal Nanostructure with a Combination of 0D Nanoparticles, 1D Nanofibers, and 2D Nanosheets: An Efficient Bifunctional Catalyst for Zinc‐Air Batteries

“…For comparison, a device was assembled using the same amount of 20 wt % Pt/C + RuO 2 catalyst with the (Figure 7a). [57,58] The Co@CNFs-50-800 and Pt/C + RuO -based Zn-air batteries showed similar open circuit voltages of 1.401 V (Figure 7b) and 1.46 V ( Figure S21), respectively. The discharge and charge polarization curves (IÀ V curves) of the batteries are shown in Figure S22, where we can see the onset potential of Pt/C + RuO 2 was slightly slower than that of the Co@CNFs-50-800 catalyst in the charging curves.…”

“…For comparison, a device was assembled using the same amount of 20 wt % Pt/C+RuO 2 catalyst with the mass ratio of 1 : 1 as the benchmark. A home‐made cell was assembled using 6.0 M KOH+0.2 M zinc acetate aqueous solution as the electrolyte and a polished zinc foil as the anode (Figure 7a) [57,58] . The Co@CNFs‐50‐800 and Pt/C+RuO 2 ‐based Zn‐air batteries showed similar open circuit voltages of 1.401 V (Figure 7b) and 1.46 V (Figure S21), respectively.…”

Electronic modulation and interface engineering of electrospun nanomaterials‐based electrocatalysts toward water splitting

“…In fact, to tune the OER performance, the interface between the active electrocatalyst and CNFs is very important 171‐198 . Li et al 197 developed an electrospinning and carbonization process to prepare CoFe 2 O 4 nanoparticles encapsulated in N‐doped CNFs (CoFe 2 O 4 /NCNFs) as an OER electrocatalsyt.…”

Synergistic heat treatment derived hollow-mesoporous-microporous Fe–N–C-SHT electrocatalyst for oxygen reduction reaction

“…A hierarchical porous structure of the catalyst is essential, with macropores facilitating the transfer of reactants and products, mesopores providing large specific surface areas, and micropores offering high-density active sites [13,26]. Metal-organic frameworks (MOFs) have been utilized as potential precursors to prepare M-N-C based ORR catalysts because of their large specific surface areas (>1,000 m 2 g −1 ), uniform hierarchical porous structures, high nitrogen and carbon contents, high structural stability, and ease of doping [27][28][29][30][31].…”