The Proportion of Fe‐N_X, N Doping Species and Fe₃C to Oxygen Catalytic Activity in Core‐Shell Fe‐N/C Electrocatalyst

Abstract

Ab ifunctional oxygen electrocatalyst composed of iron carbide( Fe 3 C) nanoparticles encapsulatedb yn itrogen doped carbon sheetsi sr eported. X-ray photoelectron spectroscopy and X-ray absorption neare dge structure revealed the presence of severalk inds of active sites (FeÀN x sites, N doping sites) and the modulated electron structure of nitrogen doped carbon sheets. Fe 3 C@N-CSs shows excellent oxygen evolution and oxygen reduction catalytic activity owing to the modulated electron structure by encapsulated Fe 3 Cc orev ia biphasic interfaces electron interaction, which can lower the free energy of intermediate, strengthen the bondings trength and enhance conductivity.M eanwhile, the contribution of the FeÀN x sites, Nd oping sites and the effect of Fe 3 Cc ore for the electrocatalytic oxygen reaction is originally revealed. The Fe 3 C@N-CSsa ir electrode-based zincair battery demonstrates ah igh open circuit potentialo f 1.47 V, superior charge-discharge performance and long lifetime, which outperforms the noble metal-based zinc-air battery.

Iron carbide nanoparticles supported on an N-doped carbon porous framework as a bifunctional material for electrocatalytic oxygen reduction and supercapacitors

“…It is worth noting that the peak at 284.8 eV (sp2 C–C) of Fe 3 C/PNCF is of the highest proportion, implying that the graphite carbon increases and the charge can be redistributed and optimized, thus reinforcing the electrical conductivity. 46,47 In addition, the binding energy of C–N and CN in the C 1s spectrum shifts to lower values while the binding energy of pyridinic-N shifts to a higher value when comparing Fe 3 C/PNCF with Fe 3 C/NC and Fe 3 C/PNC. This could be ascribed to the possibility that encapsulated Fe 3 C may contribute to modulating the electron structure of the surrounding N-doped carbon matrix, which is induced by the different binding energies between Fe 3 C and the N-doped carbon matrix.…”

“…It is worth noting that the peak at 284.8 eV (sp2 C-C) of Fe 3 C/PNCF is of the highest proportion, implying that the graphite carbon increases and the charge can be redistributed and optimized, thus reinforcing the electrical conductivity. 46,47 In addition, the binding energy of C-N and CvN in the C 1s spectrum shifts to lower values while the binding energy of pyridinic-N shifts to a higher value when comparing Fe 3 C/PNCF with Fe 3 C/NC and Fe 3 C/PNC.…”

“…The electronic interactions on Fe 3 C/N-doped carbon heterointerfaces may facilitate charge transfer during the oxygen electrocatalysis process, thus leading to high ORR activity. 2,47 Consequently, the as-prepared Fe 3 C/PNCF nanocomposites are expected to be capable of good performance in ORR electrocatalysis and supercapacitors.…”