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Updated: Sep 16, 2025
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Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles
Published on: October 27, 2018
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Structural, Compositional, and Morphological Interrelationships in Rocksalt (FeCoMnMgZn)O High Entropy Oxide
Gaurav R Dey, Simeon Teklu, Zixiao Shi1
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.
Journal of the American Chemical Society
|July 4, 2025
Summary
Colloidal synthesis of high entropy oxide nanocrystals was achieved, revealing reaction pathways and enabling morphological control. These novel nanocrystals show promise as electrocatalysts for the oxygen evolution reaction.
Area of Science:
- Materials Science
- Nanotechnology
- Inorganic Chemistry
Background:
- Colloidal synthesis of high entropy oxides (HEOs) is challenging due to unknown reaction pathways.
- Limited understanding of HEO formation and growth hinders control over nanocrystal morphology.
Purpose of the Study:
- To achieve colloidal synthesis of rocksalt-type (FeCoMnMgZn)O nanocrystals with controlled morphologies.
- To elucidate the reaction pathways and intermediate species involved in HEO formation.
- To investigate the structural properties and catalytic activity of the synthesized HEO nanocrystals.
Main Methods:
- Colloidal synthesis of (FeCoMnMgZn)O nanocrystals.
- Reaction pathway analysis.
- Atomic resolution imaging (e.g., TEM).
- Electrochemical testing for oxygen evolution reaction (OER).
Main Results:
- Successfully synthesized rocksalt-type (FeCoMnMgZn)O nanocrystals with diverse morphologies.
- Identified a Fe-rich spinel-type intermediate, indicating competing reactivities.
- Observed a 1.73% lattice expansion in nanocrystals compared to bulk FeO.
- (FeCoMnMgZn)O nanocrystals demonstrated activity as electrocatalysts for OER.
Conclusions:
- Competing reactivities in colloidal synthesis dictate HEO composition and morphology.
- Atomic-level insights into HEO formation pathways are crucial for morphological control.
- Synthesized HEO nanocrystals are promising for electrochemical applications like OER.
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