Electrospun Fe₂C-loaded carbon nanofibers as efficient electrocatalysts for oxygen reduction reaction

Abstract

Carbon-based non-precious metal catalysts have been regarded as the most promising alternatives to the state-of-art Pt/C catalyst for the oxygen reduction reaction (ORR). However, there are still some unresolved challenges such as agglomeration of nanoparticles, complex preparation process and low production efficiency, which severely hamper the large-scale production of non-precious metal catalysts. Herein, a novel carbon-based non-precious metal catalyst, i.e. iron carbide nanoparticles embedded on carbon nanofibers (Fe 2 C/CNFs), prepared via the direct pyrolysis of carbon-and iron-containing Janus fibrous precursors obtained by electrospinning. The Fe 2 C/CNF catalyst shows uniform dispersion and narrow size distribution of Fe 2 C nanoparticles embedded on the CNFs. The obtained catalyst exhibits positive onset potential (0.87 V versus RHE), large kinetic current density (1.9 mA cm −2 ), and nearly follows the effective four-electron route, suggesting an outstanding electrocatalytic activity for the ORR in 0.1 M of KOH solution. Besides, its stability is better than that of the commercial Pt/C catalyst, due to the strong binding force between Fe 2 C particles and CNFs. This strategy opens new avenues for the design and efficient production of promising electrocatalysts for the ORR.

Electrospinning Janus Type CoOx/C Nanofibers as Electrocatalysts for Oxygen Reduction Reaction

“…1. Based on our previous work [20], a plastic syringe filled with two types of matching electrospinning precursor solutions was assembled by a homemade electrospinning spinneret under the best electrospinning parameters, as-spun Janus nanofibers…”

Recent Advances in Enhancing Oxygen Reduction Reaction Performance for Non‐Noble‐Metal Electrocatalysts Derived from Electrospinning

“…[ 78–80 ] In Figure 9d, Liu et al designed Janus nanofibers with iron carbide nanoparticles embedded on CNFs by a homemade parallel spinneret showing 0.87 V ORR half‐wave potential. [ 52 ] From the scanning electron microscopy (SEM) image in Figure 9e, the porous part, which is located at one‐half of this Janus structure, is derived from PVP, and could expose more active sites. When using the parallel spinneret to prepare Janus‐structured nanofibers, the part of the plastic extension tube should be longer than the steel extension tube to avoid the convergence of the two kinds of solutions before electrospinning.…”

“…[ 49 ] Several unique spinnerets, such as coaxial and parallel spinnerets, are selected to obtain fibers with core–shell, [ 50 ] hollow, or Janus structure after heat treatments. [ 51,52 ] The distance between the spinneret and collector determines the sufficiency extent of fiber stretching and curing. [ 53 ] A rotating drum and a static disc as two types of collectors are usually reported, of which the rotating drum keeps the fibers orientation arrangement.…”

Core-Shell Fe3O4@NCS-Mn Derived from Chitosan-Schiff Based Mn Complex with Enhanced Catalytic Activity for Oxygen Reduction Reaction

“…Therefore, efforts have been made to develop Pt alternative catalysts for ORR. In alkaline media, electrocatalysts with various categories have been developed, further, the corresponding mechanisms have been explored, including nonmetal-doped carbon materials [4][5][6][7][8], carbon-transition metal hybrids [9][10][11][12][13][14][15][16][17][18][19][20], metal organic framework-modified nitrogen-doped graphene [21][22][23], and transition metal oxides [24][25][26][27][28]. Nonmetal heteroatom doped carbon materials and transition metal oxides have especially been given attention due to their advantages of high electron conductivity and favorable redox reversibility, respectively [29,30].…”