Electrospinning Hetero‐Nanofibers of Fe₃C‐Mo₂C/Nitrogen‐Doped‐Carbon as Efficient Electrocatalysts for Hydrogen Evolution

Abstract

Heterostructured electrocatalysts with multiple active components are expected to synchronously address the two elementary steps in the hydrogen evolution reaction (HER), which require varied hydrogen-binding strength on the catalyst surface. Herein, electrospinning followed by a pyrolysis is introduced to design Fe C-Mo C/nitrogen-doped carbon (Fe C-Mo C/NC) hetero-nanofibers (HNFs) with tunable composition, leading to abundant Fe C-Mo C hetero-interfaces for synergy in electrocatalysis. Owing to the strong hydrogen binding on Mo C and the relatively weak one on Fe C, the hetero-interfaces of Fe C-Mo C remarkably promote HER kinetics and intrinsic activity. Additionally, the loose and porous N-doped carbon matrix, as a result of Fe-catalyzed carbonization, ensures the fast transport of electrolytes and electrons, thus minimizing diffusion limitation. As expected, the optimized Fe C-Mo C/NC HNFs afforded a low overpotential of 116 mV at a current density of -10 mA cm and striking kinetics metrics (onset overpotential: 42 mV, Tafel slope: 43 mV dec ) in 0.5 m H SO , outperforming most recently reported noble-metal-free electrocatalysts.

N‐Doped Carbon Nanotubes Encapsulating Ni/MoN Heterostructures Grown on Carbon Cloth for Overall Water Splitting

“…Furthermore, a distinct lattice spacing of 0.28 nm is observed (Figure f), attributed to the (002) plane of MoN (PDF#89‐5024), which confirm the formation of MoN nanoparticles. The interface exists between Ni and MoN nanoparticles in the heterostructures might lead to higher intrinsic catalytic activity and exposing more active sites . Besides, the elemental mapping was employed to further examine the composition of Ni/MoN@NCNT/CC.…”

Molybdenum Carbide‐Oxide Heterostructures: In Situ Surface Reconfiguration toward Efficient Electrocatalytic Hydrogen Evolution

“…(c) Comparison of η 10 of Mo 2 C‐MoO x /CC( 2 ) with Pt/C and recently reported Mo x C electrocatalysts (ref. samples 1: Mo 2 C@NC nanomesh; 2: Mo 2 C/G‐NCS; 3: Mo 2 C/MoN/NG; 4: Mo/β‐Mo 2 C; 5: N‐Mo 2 C NSs; 6: Mo 2 C/CF; 7: N, P‐Mo x C NF; 8: Fe 3 C‐Mo 2 C/NC; 9: Mo 2 C@GC core–shell nanowire; 10: MoC‐Mo 2 C; 11: Co‐Mo 2 C nanowires; 12: Mo 2 C/CLCN; 13: Mo‐Mo 2 C; 14: MoO 2 ‐Mo 2 C/C; 15: α‐MoC 1− x /β‐ Mo 2 C; 16: 3DHP‐Mo 2 C; 17: Mo 2 C@NC@MoS x ;). (d) Estimation of C dl by plotting the current density variation (Δ j =( j a − j c )/2, at 150 mV vs. RHE.…”

Activation of Ternary Transition Metal Chalcogenide Basal Planes through Chemical Strain for the Hydrogen Evolution Reaction

“…The ECSA would provide the intrinsic activity of the catalyst for the optimizationo fa ctive sites. [52][53][54] Cyclic voltammetry (CV) wasp erformed for all as-synthesized samples between À0.4 Vt o À0.2 Vatv ariouss can rates. The corresponding capacitive current densities at À0.3 Vv ersus NHE (non-Faradaic region) were plotteda saf unctiono fs can rate as shown in Figure3c.…”