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

• Ability of pristine and Ni-decorated AlN and SiC nanotubes as an detecting device for C2H4/C2H6.
• C2H4/C2H6 molecule weakly physisorbed on the outer surface of AlN and SiC nanotubes.
• C2H4/C2H6 tends to be chemisorbed/physisorbed onto the Ni-decorated AlNNT and SiCNT.
• Ni-doped nanotubes a promising candidate for monitoring C2H4/C2H6 molecule.
• A considerable charge transfer reduced the energy gap of nanotube/Ni-hydrocarbon systems.

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/−179 kJ/mol for AlNNT/Ni and −96/−202 kJ/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.

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