Research Progress of High-Entropy Oxides as Oxygen Evolution Reaction Catalysts

Equimolar or nearly molar mixtures of five or more metals are used to create high-entropy oxides (HEOs). HEOs also possess the kinetic slow diffusion effect, structural lattice distortion, the thermodynamic high-entropy effect, and the cocktail effect. Consequently, a growing number of scientists are investigating high-entropy oxides. High active site density, low overpotential, and entropic stabilization effects are the main reasons why HEOs now show good electrocatalytic oxygen evolution reaction. However, the complexity of the elemental composition, organization, and surface morphology of high-entropy oxides limits the use of HEOs. The development of HEOs and the mechanisms behind OER are reviewed in this work, along with a description of the OER response pathways and evaluation standards. The OER performance of HEOs with diverse organizational structures is reviewed in this research because HEOs come in a variety of kinds. Additionally, when HEOs are utilized as carriers, the trend of OER performance is examined. Lastly, potential future development problems and opportunities for HEO electrocatalysts are discussed.