A comparative study of alkali metal adsorptions on graphite using quantum mechanical calculations

Zhu, Z. H. and Lu, G. Q. (2004) A comparative study of alkali metal adsorptions on graphite using quantum mechanical calculations. Langmuir, 20 24: 10751-10755.

Document type:	Journal Article
Collections:	Excellence in Research Australia (ERA) - Collection School of Chemical Engineering Publications

Author(s)	Zhu, Z. H. Lu, G. Q.
Title	A comparative study of alkali metal adsorptions on graphite using quantum mechanical calculations
Journal name	Langmuir
Publication date	2004
Sub-type	Article
Volume number	20
Issue number	24
ISSN	0743-7463
Start page	10751
End page	10755
Total pages	5
Place of publication	Washington, U.S.
Publisher	American Chemical Society
Language	eng
Abstract	A comprehensive study has been conducted to compare the adsorptions of alkali metals (including Li, Na, and K) on the basal plane of graphite by using molecular orbital theory calculations. All three metal atoms prefer to be adsorbed on the “middle hollow site” above a hexagonal aromatic ring. A novel phenomenon was observed, that is, Na, instead of Li or K, is the weakest among the three types of metal atoms in adsorption. The reason is that the SOMO (single occupied molecular orbital) of the Na atom is exactly at the middle point between the HOMO and the LUMO of the graphite layer in energy level. As a result, the SOMO of Na cannot form a stable interaction with either the HOMO or the LUMO of the graphite. On the other hand, the SOMO of Li and K can form a relatively stable interaction with either the HOMO or the LUMO of graphite. Why Li has a relatively stronger adsorption than K on graphite has also been interpreted on the basis of their molecular-orbital energy levels.
Keyword(s)	Li Na K Adsorption