Ammonia Adsorption on SiC Nanotubes: A Density Functional Theory Investigation

Abstract

The adsorption of NH₃ on a (5, 0) single-walled SiC nanotube is studied by using the density functional theory approach. The silicon atoms in sites on SiCNT surface is the most stable adsorption site for N pointing of NH₃ toward the nanotube surface, with a binding energy of −1.36 eV (−31.35 kcal mol⁻¹) and a Si–N binding distance of 1.972 Å. We also have tested the stability of the NH₃-adsorbed SiCNT with ab initio molecular dynamics calculations, which have been carried out at room temperature. Furthermore, the adsorption of NH₃ on the single-walled carbon nanotubes has been investigated. Our first-principles calculations predict that the NH₃ adsorptive capability of silicon carbide nanotubes is much better than that of carbon nanotubes. This demonstrates that SiCNTs could be a promising material for gas detection and energy storage.

Keywords:

• Adsorption
• ammonia
• DFT
• ab initio MD
• SiCNTs
• CNTs
• sensors

Acknowledgments

We thank Dr. Saeed Yeganegy for many fruitful discussions. This work was supported by the Islamic Azad University of Ghaemshahr.