Defect-activated surface reconstruction: mechanism for triggering the oxygen evolution reaction activity of NiFe phosphide

Abstract

The nickel-iron phosphide (NiFeP) electrocatalysts have been considered as one kind of promising non-precious metal catalysts for overall water splitting (OWS). However, despite numerous reports in this field, the origin...

Constructing Amorphous–Crystalline Interfaces of Nickel–Iron Phosphides/Oxides for Oxygen Evolution Reaction

“…Notably, NiFe oxides/oxyhydroxides with higher average valence states have been demonstrated as efficient OER electrocatalysts in an alkaline electrolyte because of the synergistic effect between Ni and Fe, − which could adjust the affinity of O on the surface catalytic sites to an optimal value and promote the generation of O–O bonds and oxygen evolution. By a comparison of the XRD patterns of NiFeP x /NiFeO x before and after the OER test (Figure d), no new diffraction peaks are observed, manifesting that NiFe oxides/oxyhydroxides are amorphous, which is consistent with previous reports. , …”

“…By a comparison of the XRD patterns of NiFeP x / NiFeO x before and after the OER test (Figure 5d), no new diffraction peaks are observed, manifesting that NiFe oxides/ oxyhydroxides are amorphous, which is consistent with previous reports. 46,47 ■ CONCLUSIONS In summary, we have successfully fabricated a nickel−iron phosphides/oxides nanosheet heterostructure as a remarkably efficient OER electrocatalyst in alkaline conditions via surface phosphorization. The impressive OER performance is attributed to the construction of ample amorphous−crystalline interfaces with abundant O v , which not only increase the amount and inherent electrocatalytic activity of active sites but also facilitate the charge-transfer rate and conductivity of the materials.…”

A Facile Molecular Approach to Amorphous Nickel Pnictides and Their Reconstruction to Crystalline Potassium‐Intercalated γ‐NiOOHx Enabling High‐Performance Electrocatalytic Water Oxidation and Selective Oxidation of 5‐Hydroxymethylfurfural

“…[ 23,31,90,91 ] The herein synthesized nickel pnictides readily and completely undergo the beneficial reconstruction process in contrast to the formation of a core‐shell type structure. [ 23,92–95 ] As reported previously, a reason for this is their amorphous nature, which includes disorder, coordinatively unsaturated sites, and thermodynamic instability. [ 26–30 ] A remarkable feature of the herein observed reconstruction is the transition of an amorphous precatalyst to a nanocrystalline catalyst, as usually, the reconstruction leads to the formation of amorphous phases even if crystalline precursors are applied.…”

Constructing Fe/Ni atomic interfaces in Fe-doped Ni(OH)2with single-phase structures for efficient oxygen evolution

“…Hydrogen, marked by high energy density and environmental friendliness and produced via water splitting has attracted intensive attention. 1,2 However, hydrogen production efficiency is severely restricted by oxygen evolution reaction (OER) owing to their sluggish kinetics and larger overpotential resulting from complicated multistep-proton-coupled-electron transfer. 3,4 Although Ir/Ru-based oxide catalysts exhibit outstanding catalytic activity, their scarcity and high cost severely impede their large-scale applications.…”