2D Nanostructures of CoFe2O4 and NiFe2O4: Efficient Oxygen Evolution Catalyst

A high-performance bimetallic cobalt iron oxide catalyst for the oxygen evolution reaction

Herein, a facile solvothermal approach was designed to produce the CoFe₂O₄ nanospheres with unique porous structure. As an efficient electrocatalyst for OER, the CoFe₂O₄ nanospheres performed high performance.

Magnetically retrievable ferrite nanoparticles in the catalysis application

In the present review, we summarized the applications of magnetic spinel ferrite nanoparticles as catalysts in organic reactions and transformations. Catalytic applications are comprised of using mostly cobalt, nickel, copper, and zinc ferrites, along with their mixed-metal combinations based on nano ferrites. The spinel ferrites (SFs) are gained principally by wet-chemical, sol-gel or co-precipitation methods, more infrequently by the mechanical high-energy ball milling, spark plasma sintering, sonochemical technique, microwave heating or hydrothermal route. Catalytic processes with the application of ferrite nanoparticles are included decomposition (in particular photocatalytic), reactions of dehydrogenation, oxidation, alkylation, CC coupling, removing organic/inorganic contaminants from aqueous solutions. As significant and remarkable advantages, ferrite nanocatalysts not only are environmentally benign and compatible with green chemistry aspects but also can be simply recovered from reaction systems and recycled up to several times almost without significant loss of their catalytic activity.

Spinel oxide CoFe2O4 grown on Ni foam as an efficient electrocatalyst for oxygen evolution reaction

The effect of the oxygen evolution reaction (OER) is important in water splitting. In this work, we develop sphere-like morphology spinel oxide CoFe2O4/NF by hydrothermal reaction and calcination, and the diameter of the spheres is about 111.1 nm. The CoFe2O4/NF catalyst exhibits excellent electrocatalytic performance with an overpotential of 273 mV at a current density of 10 mA cm-2 and a Tafel slope of 78 mV dec-1. The cycling stability of CoFe2O4/NF is remarkable, and it only increased by 5 mV at a current density of 100 mA cm-2 after 3000 cycles. Therefore, this simple method to prepare CoFe2O4/NF can enhance the OER properties of electrocatalysts, which makes CoFe2O4/NF a promising material to replace noble metal-based catalysts for the oxygen evolution reaction.

Recent Advances in the Development of Water Oxidation Electrocatalysts at Mild pH

Developing anodic oxygen evolution reaction (OER) electrocatalysts with high catalytic activities is of great importance for effective water splitting. Compared with the water-oxidation electrocatalysts that are commonly utilized in alkaline conditions, the ones operating efficiently under neutral or near neutral conditions are more environmentally friendly with less corrosion issues. This review starts with a brief introduction of OER, the importance of OER in mild-pH media, as well as the fundamentals and performance parameters of OER electrocatalysts. Then, recent progress of the rational design of electrocatalysts for OER in mild-pH conditions is discussed. The chemical structures or components, synthetic approaches, and catalytic performances of the OER catalysts will be reviewed. Some interesting insights into the catalytic mechanism are also included and discussed. It concludes with a brief outlook on the possible remaining challenges and future trends of neutral or near-neutral OER electrocatalysts. It hopefully provides the readers with a distinct perspective of the history, present, and future of OER electrocatalysts at mild conditions.

Facile synthesis of yolk–shell structured ZnFe2O4 microspheres for enhanced electrocatalytic oxygen evolution reaction

Yolk–shell structured ZnFe₂O₄ microspheres with excellent OER performance are synthesized via a facile solvothermal method and annealing treatment.

An iron incorporation-induced nickel hydroxide multiphase with a 2D/3D hierarchical sheet-on-sheet structure for electrocatalytic water oxidation

An Fe-incorporated Ni(OH)₂ multiphase with a unique 2D/3D hierarchical sheet-on-sheet structure exhibits superior catalytic activity contributed by synergistic effects, enhanced electron transport and well-exposed active sites.