Silicon Carbide Based Nanotubes as a Sensing Material for Gaseous H₂SiCl₂

The ability of carbon- and silicon-based nanotubes, including pure carbon, silicon carbide, and Ge-doped silicon carbide nanotubes (CNT, SiCNT, SiCGeNT, respectively), for sensing highly toxic dichlorosilane (H2SiCl2) are investigated using quantum chemistry calculations. The intermolecular interactions between the sensing material and the gas molecule have been investigated with the density functional theory calculations with a functional that includes dispersion terms. The selected method employed is B3LYP-D3 (GD3BJ)/6-311G(d), while other functionals including PBE0, ωB97XD, and M06-2X have been used for comparison. The quantum theory of atoms in molecules (QTAIM) analysis is employed to check the type of intermolecular interactions. Natural bond orbital (NBO) calculations have been used to deduce the bond orders. The findings of this work indicate that the adsorption of the H2SiCl2 is a physisorption process, which is very desirable for its function as a sensing element. The Ge-doped nanotube offers maximum adsorption energy in comparison to CNT and SiCNT.