Title
Structural transformation of layered double hydroxides: An in situ TEM analysis
Author
Hobbs, C.
Jaskaniec, S.
McCarthy, E.K.
Downing, C.
Opelt, K.
Güth, K.
Shmeliov, A.
Mourad, M.C.D.
Mandel, K.
Nicolosi, V.
Publication year
2018
Abstract
A comprehensive nanoscale understanding of layered double hydroxide thermal evolution is critical for their current and future applications as catalysts, flame retardants and oxygen evolution performers. In this report, we applied in situ transmission electron microscopy to extensively characterise the thermal progressions of nickel-iron containing LDH nanomaterials. The combinative approach of TEM and selected area electron diffraction yielded both a morphological and crystallographic understanding of such processes. As the Ni-Fe LDH nanomaterials are heated in situ, an amorphization occurred at 250 °C, followed by a transition to a heterogeneous structure of NiO particles embedded throughout a NiFe2O4 matrix at 850 °C, confirmed by high-resolution TEM and scanning TEM. Further electron microscopy characterisation methodologies of energy-filtered TEM were utilised to directly observe these mechanistic behaviours in real time, showing an evolution and nucleation to an array of spherical NiO nanoparticles on the platelet surfaces. The versatility of this characterisation approach was verified by the analogous behaviours of Ni-Fe LDH materials heated ex situ as well as parallel in situ TEM and SAED comparisons to that of an akin magnesium-aluminium containing LDH structure. The in situ TEM work hereby discussed allows for a state-of-the-art understanding of the Ni-Fe material thermal evolution. This is an important first, which reveals pivotal information, especially when considering LDH applications as catalysts and flame retardants. © 2018, The Author.
Subject
Aluminum alloys
Binary alloys
Catalysts
Electron diffraction
Flame retardants
High resolution transmission electron microscopy
In situ processing
Nanostructured materials
Nickel oxide
Transmission electron microscopy
Energy filtered TEM
Future applications
Heterogeneous structures
High-resolution TEM
In situ transmission electron microscopy
Layered double hydroxides
Selected area electron diffraction
Structural transformation
Magnesium alloys
To reference this document use:
http://resolver.tudelft.nl/uuid:ce5a708a-4d02-4a9e-a5f7-c3275e3ef897
DOI
https://doi.org/10.1038/s41699-018-0048-4
TNO identifier
844186
Publisher
Nature Publishing Group
ISSN
2397-7132
Source
npj 2D Materials and Applications, 2 (1)
Article number
4
Document type
article