A density functional theory study of CO2 and N2 adsorption on aluminium nitride single walled nanotubes

Abstract

Strong binding of isolated carbon dioxide (CO₂) on aluminium nitride (AlN) single walled nanotubes is verified using two different functionals. Two optimized configurations corresponding to physisorption and chemisorption are linked by a low energy barrier, such that the chemisorbed state is accessible and thermodynamically favored at low temperatures. In contrast, N₂ is found only to form a physisorbed complex with the AlN nanotube, suggesting the potential application of aluminium nitride based materials for CO₂ fixation. The effect of nanotube diameter on gas adsorption properties is also discussed. The diameter is found to have an important effect on the chemisorption of CO₂, but has little effect on the physisorption of either CO₂ or N₂.