Tunable High Entropy Lanthanide Oxide Microspheres via Confined Electroprecipitation in Emulsion Droplet Scaffolds.

Emergent high entropy nanomaterials and their associated complex surface structure hold promise to unlock unique catalytic intermediate pathways and photonic/plasmonic interactions; however, synthetic strategies to tune the size, morphological, and stoichiometric properties remain limited. This work demonstrates a confined electro-precipitation mechanism for the formation of tunable, high-entropy oxide microspheres within emulsion droplet scaffolds. This mechanism complements a traditional confined electrodeposition mechanism and explains the previously observed anomalous formation of thermodynamically unfavorable particles, including lanthanide species.