NMR and X-ray absorption study of lithium intercalation in micro- and nanocrystalline anatase
- Univ. of New South Wales, Sydney (Australia). School of Chemistry
The intercalation of Li into micro- and nanocrystalline anatase xerogel powders using n-butylithium and various preparation conditions has been studied by Li and Li solid-state NMR and X-ray absorption spectroscopy. The orthorhombic lithium titanate phase which forms for Li/Ti < 0.56 undergoes further structural modification as the Li/Ti ratio increases to 0.70. NMR shows the existence of one type of lithium environment in microcrystalline samples when Li/Ti {le} 0.30 and two lithium environments when Li/Ti > 0.30. These two lithium environments are assigned to Li{sup +} ions in similar structural sites that are uncoupled (species A) and weakly coupled (species B) to conduction band electrons. Nanocrystalline anatase samples produced by sol-gel methods differ from microcrystalline anatase in that the proportion of species A is greater. NMR further suggests that the coordination number of species A cannot be greater than five while no definite conclusions could be reached from NMR concerning species B. Titanium K-edge X-ray absorption near edge structure (XANES) provides a method of monitoring changes in electronic structure as Li is intercalated. Extended X-ray absorption fine structure (EXAFS) analysis provides information on the Ti local environment which changes considerably with the degree of intercalation in microcrystalline samples. For nanocrystalline anatase samples greater amounts of intercalation can be achieved which dramatically affects both the XANES and the EXAFS.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- OSTI ID:
- 696618
- Journal Information:
- Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 8 Vol. 11; ISSN CMATEX; ISSN 0897-4756
- Country of Publication:
- United States
- Language:
- English
Similar Records
Anatase-TiO2 Nanomaterials: Analysis of Key Parameters Controlling Crystallization
Structural and electronic properties of sol-gel titanium oxides studied by X-ray absorption spectroscopy
In situ X-ray diffraction of lithium intercalation in nanostructured and thin film anatase TiO{sub 2}
Journal Article
·
Sun Dec 31 23:00:00 EST 2006
· Journal of the American Chemical Society
·
OSTI ID:959769
Structural and electronic properties of sol-gel titanium oxides studied by X-ray absorption spectroscopy
Journal Article
·
Wed Dec 23 23:00:00 EST 1998
· Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
·
OSTI ID:315995
In situ X-ray diffraction of lithium intercalation in nanostructured and thin film anatase TiO{sub 2}
Journal Article
·
Wed Sep 01 00:00:00 EDT 1999
· Journal of the Electrochemical Society
·
OSTI ID:20003166