AlN Nanotube Decorated with Small Tin Oxide Clusters as a Novel CH₄ Sensing Material

The success of carbon nanotubes has triggered a great deal of research interest in other one-dimensional nanomaterials with the aim of designing innovative nanostructures with attractive and distinctive attributes for applications in sensing gas molecules and toxic substances. In the present study, first-principles density functional theory calculations were exploited to assess the capability of the small tin oxide cluster (Sn x O y )-decorated (6,0)aluminum nitride (AlN) nanotube for detecting methane(CH 4 ) in terms of energetic, structural, and electronic properties. We found that Sn x O y clusters were chemisorbed on the surface of the AlN nanotube due to the considerable adsorption energy and the notable charge transfer from the former to the latter. Further calculations demonstrate that the energy band gap and work function of the AlN nanotube were reduced in the presence of additives. Benefiting from the higher affinity of Sn x O y toward the CH 4 molecule, the Sn 3 O 3 -decorated AlN nanotube exhibited the greatest CH 4 adsorption energy. The electrical conductivity increased as the energy band gap and effective mass decreased dramatically. Additionally, the type of Sn 3 O 3 -decorated AlN nanotube changed from a p-type semiconductor to an n-type one after adsorbing the CH 4 molecule. Therefore, the Sn 3 O 3 -decorated AlN nanotube endows great promise as a thermopower-based, resistance-based, and Seebeck-effect-based CH 4 sensing material.