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Plane‐wave density functional theory investigation of adsorption of 2,4,6‐trinitrotoluene on al‐hydroxylated (0001) surface of (4 × 4) α‐alumina
Author(s) -
Shukla Manoj K.,
Hill Frances
Publication year - 2014
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.23712
Subject(s) - adsorption , density functional theory , trinitrotoluene , van der waals force , hydrogen bond , molecule , chemistry , hydroxylation , computational chemistry , chemical physics , materials science , organic chemistry , enzyme , explosive material
This article reports the results of the theoretical investigation of adsorption of 2,4,6‐trinitrotoluene (TNT) on Al‐hydroxylated (0001) surface of (4 × 4) α‐alumina (α‐Al 2 O 3 ) using plane‐wave Density Functional Theory. Sixteen water molecules were used to hydroxylate the alumina surface. The Perdew–Burke–Ernzerhof functional and the recently developed van der Waals functional (vdW‐DF2) were used. The interaction of electron with core was accounted using the Vanderbilt ultrasoft pseudopotentials. It was found that hydroxylation has significant influence on the geometry of alumina and such changes are prominent up to few layers from the surface. Particularly, due to the Al‐hydroxylation the oxygen layers are decomposed into sublayers and such partitioning becomes progressively weaker for interior layers. Moreover, the nature of TNT adsorption interaction is changed from covalent type on the pristine alumina surface to hydrogen‐bonding interaction on the Al‐hydroxylated alumina surface. TNT in parallel orientation forms several hydrogen bonds compared to that in the perpendicular orientation with hydroxyl groups of the Al‐hydroxylated alumina surface. Therefore, the parallel orientation will be present in the adsorption of TNT on Al‐hydroxylated (0001) surface of α‐alumina. Further, the vdW‐DF2 van der Waals functional was found to be most suitable and should be used for such surface adsorption investigation. © 2014 Wiley Periodicals, Inc.