ADSORPTION OF DIBENZOXAZEPINE GAS ON TRANSITION METAL-DOPED SILICON CARBIDE NANOTUBES: A THEORETICAL INVESTIGATION

Dibenzoxazepine (CR) molecule is highly toxic gas, therefore, the development of highly sensitive materials for their adsorption and detection is desirable. Density functional theory (DFT) calculation was performed to study the adsorption behavior of CR gas on the pristine and transition metal (TM=Sc, Ti, Y, Zr, La, and Hf) –doped silicon carbide nanotubes (SiCNT) at both Si and C sites. The most stable adsorption configurations, adsorption distances, adsorption energies, charge transfers, energy gaps, orbital distributions, and density of states are obtained to understand the impacts of CR gas on the adsorption abilities and electronic properties of the pristine and TM–doped SiCNT surfaces. The results show that the pristine SiCNT exhibits low adsorption ability to CR gas. Conversely, the SiCNT doping with TM atom at Si and C sites enhances adsorption ability to CR gas. The strong adsorption of CR gas on TM–doped SiCNT surface is due to more favorable orbital interaction as well as shorter adsorption distance and larger charge transfer than pristine SiCNT. Moreover, the results reveal that the adsorption of CR gas significant changes in the electronic properties of TM–doped SiCNT. Therefore, the doping of TM atoms on SiCNT at both Si and C sites could enhance the adsorption ability and suitable for use as sensors for detecting CR gas.