A DFT study on electronic structure and local reactivity descriptors of pristine and carbon-substituted AlN nanotubes

Abstract

A density functional theory study was carried out to investigate the structural and electronic structure properties of pristine and carbon-substituted (6,0) aluminum nitride nanotubes (AlNNTs). We examine the usefulness of local reactivity descriptors to predict the reactivity of AlN atomic sites on the external surface of the tubes. The properties determined include the Fukui function f(k) and local softness s(k) on the surfaces of the investigated tubes. According to the values of f(k) and s(k) for the pristine AlNNT, the aluminum atoms are highly preferred sites for nucleophile addition. More especially, the aluminum atoms in middle portion show different reactivity pattern from those at the edge or cap regions of the nanotube. Our results indicate that the nitrogen atoms adjacent to the substituted carbon atoms are less reactive toward atomic hydrogen chemisorption than those in the pristine one. There is an acceptable correlation between chemisorption energies and reactivity indexes, indicating that f(k) and s(k) provide an effective means for rapidly and economically assessing the relative reactivities of finite-sized AlNNTs.