Ca12O12 nanocluster as highly sensitive material for the detection of hazardous mustard gas: Density-functional theory

Through density functional theory (DFT) computations, the adsorption behavior and electronic sensitivity of the mustard gas are scrutinized towards a Ca12O12 nanocluster. To further investigate the influence of the molecules mentioned above over the chemical and electronic characteristics of this nanocluster, we calculate the binding energies (BEs), natural bond orbital (NBO) charge transport, the frontier molecular orbitals (FMOs), as well as molecular electrostatic potential (MEP). The interaction of the mustard molecule with the Ca atoms of the cluster through the Cl-side is slightly strong, and there is a large transport of charge from the mustard to the nanocluster. Following the adsorption of the mustard gas, there is a 2.28 eV reduction in the energy gap of the HOMO as well as the LUMO of this nanocluster. This shows that the dissociation process increases the electrical conductivity of this nanocluster to a great extent. The electrical signal which is generated is conducive to the detection of the mustard molecule. Moreover, this nanocluster has a short recovery time as a sensor. In addition, the electronic characteristics and the geometry parameters of the mustard/ Ca12O12 nanocluster complexes are impacted by the solvent to a great extent. Finally, in comparison with the vacuum, the interaction among components is significantly weaker in the aqueous phase.