Theoretical investigation of ethane and ethene monitoring using pristine and decorated aluminum nitride and silicon carbide nanotubes

Abstract

The adsorption of ethane and ethene molecules on pristine and Ni-doped armchair (4,4) single walled aluminum nitride (AlN) and silicon carbide (SiC) nanotubes are investigated employing density functional theory approach. Our results indicate that the ethane/ethene molecule physisorbed onto the outer surface of AlNNT and SiCNT through weak Van der Waals interaction. On the other hand, the encapsulation of ethane/ethene onto the inner surface of considered nanotubes is endothermic and difficult to realize with an appreciable energy barrier. Compared with weak adsorption of ethane/ethene onto the pristine AlNNT and SiCNT, Ni decorated AlN and SiC nanotubes exhibit strong affinity toward the ethane/ethene molecule with remarkable negative adsorption energies about −61/−179kJ/mol for AlNNT/Ni and −96/−202kJ/mol for SiCNT/Ni systems, respectively. Based on our results, it seems that ethene tends to be chemisorbed onto the Ni-doped nanotubes, whereas the ethane-adsorption process is through strongly physisorbed process and could serve as a signal of nanosensor due to affect the electronic conductance and structural properties. These observations show that functionalized AlN and SiC nanotubes are highly sensitive toward C2H4/C2H6 molecule. Moreover, these results may be useful for the design of new types of nanosensor devices that can detect the presence of small hydrocarbon molecules.