Strongly Coupled FeNi Alloys/NiFe₂O₄@Carbonitride Layers-Assembled Microboxes for Enhanced Oxygen Evolution Reaction

Abstract

Hydrogen produced from electrocatalytic water splitting is a promising route due to the sustainable powers derived from the solar and wind energy. However, the sluggish kinetics at the anode for water splitting makes the highly effective and inexpensive electrocatalysts desirable in oxygen evolution reaction (OER) by structure and composition modulations. Metal-organic frameworks (MOFs) have been intensively used as the templates/precursors to synthesize complex hollow structures for various energy-related applications. Herein, an effective and facile template-engaged strategy originated from bimetal MOFs is developed to construct hollow microcubes assembled by interconnected nanopolyhedron, consisting of intimately dominant FeNi alloys coupled with a small NiFeO oxide, which was confined within carbonitride outer shell (denoted as FeNi/NiFeO@NC) via one-step annealing treatment. The optimized FeNi/NiFeO@NC exhibits excellent electrocatalytic performances toward OER in alkaline media, showing 10 mA·cm at η = 316 mV, lower Tafel slope (60 mV·dec), and excellent durability without decay after 5000 CV cycles, which also surpasses the IrO catalyst and most of non-noble catalysts in the OER, demonstrating a great perspective. The superior OER performance is ascribed to the hollow interior for fast mass transport, in situ formed strong coupling between FeNi alloys and NiFeO for electron transfer, and the protection of carbonitride layers for long stability.

Two Birds with One Stone: Metal–Organic Framework Derived Micro‐/Nanostructured Ni2P/Ni Hybrids Embedded in Porous Carbon for Electrocatalysis and Energy Storage

“…In addition, 89% of the initial current was maintained after 8 h by a chronopotentiometry method, further verifying the good stability of Ni 2 P/Ni@C catalyst in acid electrolyte. The outstanding durability of Ni 2 P/Ni@C catalyst should be attributed to the Ni 2 P/Ni nanocomposite delicately embedded in porous carbon shell, preventing it from agglomerating and pulverizing . Besides, in order to demonstrate the advantages of MOF‐derived route, the synthesis, characterization, and electrochemical performance of Ni 2 P/Ni/C from a sol–gel route (using citric acid as an agent) were also investigated for comparison (Figures S10–S14 and Table S4, Supporting Information).…”

Insulating Polymer‐Hydrogel Nanocomposite Thin Film ‐ Based Catalytic Electrode for Efficient Oxygen Evolution Reaction

“…The efficiency and performance of the present catalytic electrodes are comparable or superior to the powder electrocatalysts and catalytic electrodes based on [Ni,Fe]O nanoparticles reported earlier (and also commercially available catalysts like Ir/C and IrO 2 ) (Table S5). [24] The advantage of our strategy in terms of the ease and simplicity of catalyst electrode fabrication is revealed by the comparison with earlier reported methods involving temperatures up to 500°C and multiple steps with processing times ranging from 3-48 h. [27,[40][41][42][43][44] Even though electrodeposition is a simple approach and provides electrocatalysts with high efficiency and extended stability seen in chronoamperometric experiments, careful examination of the electrodes have revealed liberation of iron from the anode and its deposition on the cathode; [2] such catalyst composition changes are detrimental for practical applications. In some cases, dissolution of the surface-bound catalyst had to be compensated by adding the metal ions in the electrolyte.…”

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

“…So, it is promising to prepare an analogous MOF‐74 as the precursor for ORR catalysts, getting replacement of DHTA by DHBA. Because of the variety of MOFs’ morphology, these catalysts derived from MOFs exhibit different morphologies and structures, such as hollow spherical, nanoparticles‐embedded carbon nanotubes and porous carbon, carbon inherited rhombic dodecahedral shapes and microboxes, etc. It has been shown that the properties of these carbon materials have played a vital role in dominating the electrochemical performance of ORR.…”