A quantum chemistry study on surface reactivity of pristine and carbon-substituted AlN nanotubes

• Surface reactivity descriptors are considerably influenced by C-substitution of AlNNTs.
• The C-substitution tends to activate the surface of AlNNTs toward electrophilic/radical attack.
• An acceptable correlation between the minima of ĪS(r) and the atomic hydrogen chemisorption energies is found.

A density functional theory investigation was performed to predict the surface reactivity of pristine and carbon-substituted (6,0) single-walled aluminum nitride nanotubes (AlNNTs). The properties determined include the electrostatic potentials VS(r) and average local ionization energies ĪS(r) on the surfaces of the investigated tubes. According to computed VS(r) results, the Al/N atoms in edge or cap regions show a different reactivity pattern than those at the middle portion of the tubes. Due to the carbon-substitution at the either Al or N sites of the tubes, the negative regions associated with nitrogen atoms are stronger than before. The prediction of surface reactivity and regioselectivity using average local ionization energies has been verified by atomic hydrogen chemisorption energies calculated for AlNNTs at the B3LYP/6–31 G⁎ level. There is an acceptable correlation between the minima of ĪS(r) and the atomic hydrogen chemisorption energies, demonstrating that ĪS(r) provides an effective means for rapidly and economically assessing the relative reactivities of finite sized AlNNTs.

Computed average local ionization energies for pristine (6,0) AlNNT. Color range in eV: red > 11.2, yellow 9.9 – 11.2, green 9.9−8.7 and blue < 8.7.Figure optionsDownload as PowerPoint slide