Inductively Coupled Nonthermal Plasma Synthesis of Size-Controlled γ-Al2O3 Nanocrystals

Autor: Zichang Xiong, Himashi P. Andaraarachchi, Jacob T. Held, Rick W. Dorn, Yong-Jin Jeong, Aaron Rossini, Uwe R. Kortshagen
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Nanomaterials, Vol 13, Iss 10, p 1627 (2023)
Druh dokumentu: article
ISSN: 2079-4991
DOI: 10.3390/nano13101627
Popis: Gamma alumina (γ-Al2O3) is widely used as a catalyst and catalytic support due to its high specific surface area and porosity. However, synthesis of γ-Al2O3 nanocrystals is often a complicated process requiring high temperatures or additional post-synthetic steps. Here, we report a single-step synthesis of size-controlled and monodisperse, facetted γ-Al2O3 nanocrystals in an inductively coupled nonthermal plasma reactor using trimethylaluminum and oxygen as precursors. Under optimized conditions, we observed phase-pure, cuboctahedral γ-Al2O3 nanocrystals with defined surface facets. Nuclear magnetic resonance studies revealed that nanocrystal surfaces are populated with AlO6, AlO5 and AlO4 units with clusters of hydroxyl groups. Nanocrystal size tuning was achieved by varying the total reactor pressure yielding particles as small as 3.5 nm, below the predicted thermodynamic stability limit for γ-Al2O3.
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