TM-doped B12N12 nano-cage (TM = Mn, Fe) as a sensor for CO, NO, and NH3 gases: A DFT and TD-DFT study

Abstract

The DFT-D3 and TD-DFT calculations at B3lyp/6-311+g(d) level of the theory have been employed to study the impact of TM (TM = Mn, Fe) doping as well as the adsorption of CO, NO, and NH3 gases on the electrical and optical properties of the boron nitride nano-cage (B12N12). The binding energy, ionization potential, electron affinity, chemical hardness, and softness are estimated to emphasize the stability of the doped MnB11N12 and FeB11N12. The band gap for B12N12 is 6.748 eV while the Mn and Fe doping decrease its value to 2.199 and 2.333 eV, respectively. In addition, the doping increases the dipole moment and enhances the adsorptivity of the clusters as well as converts B12N12 from UV active material (λmax=195 nm) into visible active material (λmax=389 nm for Mn and 419 nm for Fe). Second order perturbation theory analysis of donor-acceptor interactions in the NBO basis suggests the donation-back donation mechanism for the gas-cluster interaction. The adsorption of CO, NO, and NH3 gases causes a noticeable change in the Eg of MnB11N12 (-14.37%, +22.51%, +26.6%, respectively) while affects less the Eg of B12N12 and FeB11N12, as well as leads to a considerable shift to the λmax of the UV-Vis spectra. These results may be helpful for designing a promising boron nitride gas sensor.