Interfacial‐mediated synthesis of high‐entropy oxide nanoparticles for efficient oxygen evolution

Abstract High‐entropy nanoparticles combine the intrinsic properties of high‐entropy materials with nanoscale effects to enhance electrocatalytic activity. This study employs a defect engineering strategy, utilizing the interfacial‐mediating role of oxygen vacancy‐enriched CeO 2 carriers to successfully construct a series of high‐entropy oxide (HEO) nanoparticles (NPs), Cu 0.1 Co 0.1 Nd 0.1 M 0.1 Ce 0.6 O 2 (M = Ni, Zr, Fe, Mn, Al). A surface single‐phase reconstruction in nickel‐based high‐entropy oxide nanoparticles was confirmed through high‐resolution transmission electron microscopy, while Raman spectroscopy revealed oxygen defect‐mediated regulation of interfacial electronic structures, synergistically enabling uniform multi‐metallic component dispersion. Comparative analysis of electrochemical activity demonstrates that Cu 0.1 Co 0.1 Nd 0.1 Ni 0.1 Ce 0.6 O 2 provides the most significant enhancement to the surface activity of CeO 2 . This strategy offers an effective pathway for designing defect‐mediated high‐efficiency electrocatalysts.