Constructing NiCo/Fe₃O₄ Heteroparticles within MOF-74 for Efficient Oxygen Evolution Reactions

Abstract

Metal−organic frameworks (MOF) have recently emerged as versatile precursors to fabricate functional MOF derivatives for oxygen evolution reactions (OER). Herein, we developed a controlled partial pyrolysis strategy to construct robust NiCo/Fe 3 O 4 heteroparticles within MOF-74 for efficient OER using trimetallic NiCoFe-MOF-74 as precursor. The partial pyrolysis method preserves the framework structure of MOF for effective substrates diffusion while producing highly active nanoparticles. The as-prepared NiCo/Fe 3 O 4 /MOF-74 delivered remarkably stable OER current with an overpotential as low as 238 mV at 10.0 mA cm −2 and an Tafel slop of 29 mV/dec, outperforming those of pristine NiCoFe-MOF-74, totally decomposed MOF derivatives, and most reported non-noble metal based electrocatalysts. The key for the formation of NiCo/Fe 3 O 4 /MOF-74 nanostructures is that the metals can be decomposed from NiCoFe-MOF-74 in the order of Ni, Co, and Fe under controlled heat treatment. Density functional theory calculations reveals that the underlying NiCo promotes the OER activity of Fe 3 O 4 through exchange stabilization of active oxygen species.

A general route via formamide condensation to prepare atomically dispersed metal–nitrogen–carbon electrocatalysts for energy technologies

“…[1][2][3]12 Therefore, extraordinary catalytic activity and selectivity can be expected from the MNC-based SAECs due to their largely altered and promoted reaction pathway. [13][14][15][16] Despite their extremely promising potential, most of the SAECs are currently synthesized through pyrolysis of metal salts with nitrogen and carbon sources, [17][18][19][20][21] including small molecules (such as pyrrole, 22 sodium alginate, 23 and dopamine 9 ), polymers (such as polyaniline, 24 polyphthalocyanine 8 ), carbon materials (such as graphene oxide, 17 heteroatom-doped carbon, 19 ) and MXene. 26 However, the weak coordination bonding between the metal cations and N/C sources, and the inevitable hightemperature annealing for acquiring conductivity often result in low-quality SAECs that suffer from metal aggregation.…”

Synthesis of Bimetallic Conductive 2D Metal–Organic Framework (CoxNiy‐CAT) and Its Mass Production: Enhanced Electrochemical Oxygen Reduction Activity

“…The development of electrocatalysts for energy storage or conversion is of great importance in numerous applications such as fuel cells or metal–air batteries . In general, the sluggish kinetics involved in electrocatalytic process, including the oxygen reduction reaction (ORR), is a challenging barrier to high‐performance electrocatalytic reactions.…”

Construction and Application of Interfacial Inorganic Nanostructures

“…All measurements were performed on glassy carbon electrodes in N 2 ‐saturated 1.0 M KOH. Reprinted with permission, [ 96 ] Copyright 2018, American Chemical Society.…”