Carbon monoxide monitoring using pristine and Cu-functionalized aluminum nitride and silicon carbide nanotubes; DFT study

Abstract

The adsorption of CO molecule onto the outer surfaces of pristine and functionalized AlNNT and SiCNT is investigated using density functional theory. It is found that the CO molecule in C-down mode can be physisorbed onto the AlNNT and SiCNT. Moreover the adsorption of the CO molecule onto Cu-functionalized nanotubes is also considered. The adsorption energies rise to −167.93 and −193.34kJmol−1 for AlNNT–Cu–CO and SiCNT–Cu–CO respectively. It is shown that the CO molecule in C-down mode strongly chemisorbed onto Cu-functionalized nanotubes with considerable amount of charge transfer from Cu-functionalized nanotubes to the CO molecule. In addition, results indicate that functionalized SiCNT nanotube with Cu atom is more favorable than functionalized AlNNT for CO adsorption. Natural bond orbital analysis indicates that the adsorption of CO molecule onto the Cu-functionalized nanotubes is influenced by the electronic conductance and mechanical properties, which could serve as a signal of gas sensor.