Formation of two-dimensional transition metal oxide nanosheets with nanoparticles as intermediates.
Nat Mater
; 18(9): 970-976, 2019 Sep.
Article
en En
| MEDLINE
| ID: mdl-31285617
ABSTRACT
Two-dimensional (2D) materials have attracted significant interest because of their large surface-to-volume ratios and electron confinement. Compared to common 2D materials such as graphene or metal hydroxides, with their intrinsic layered atomic structures, the formation mechanisms of 2D metal oxides with a rocksalt structure are not well understood. Here, we report the formation process for 2D cobalt oxide and cobalt nickel oxide nanosheets, after analysis by in situ liquid-phase transmission electron microscopy. Our observations reveal that three-dimensional (3D) nanoparticles are initially formed from the molecular precursor solution and then transform into 2D nanosheets. Ab initio calculations show that a small nanocrystal is dominated by positive edge energy, but when it grows to a certain size, the negative surface energy becomes dominant, driving the transformation of the 3D nanocrystal into a 2D structure. Uncovering these growth pathways, including the 3D-to-2D transition, provides opportunities for future material design and synthesis in solution.
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Bases de datos:
MEDLINE
Idioma:
En
Revista:
Nat Mater
Asunto de la revista:
CIENCIA
/
QUIMICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Estados Unidos