Exploring the adsorption of CO toxic gas on pristine and M-doped (M = Ti, Cr, Fe, Ni and Zn) GaN nanosheets

Abstract

The capability of pristine and M-doped (M = Ti, Cr, Fe, Ni and Zn) gallium nitride nanosheets (M-GaNNS) was explored at the Grimme-corrected PBE/double numerical plus polarization (DNP) level of theory for adsorbing and sensing of the carbon monoxide (CO) molecule. It was found that the binding energies for M_GaGaNNS were greater than for M_NGaNNS, indicating that Ga sites are more energetically favorable than N sites for M doping. The results demonstrated that the decrease of the energy gap for Fe_Ga,N-GaNNS and Zn_Ga-GaNNS was greater than the others. Besides, M doping of GaNNS increased the adsorption energies of CO toxic gas in comparison with pristine GaNNS. The energies of adsorption were calculated to be in the range of −0.03 (Ti_Ga-GaNNS) to −2.55 (Fe_N-GaNNS) eV. In addition, adsorption of CO gas decreased the energy gap of the GaNNS and the order was E_g (M_NGaNNS) > E_g (M_GaGaNNS). Due to the changes in the energy gaps of the GaNNS upon adsorption of CO, it was predicted that Cr_GaGaNNS and Fe_NGaNNS could be suitable for sensing of CO gas. Based on the obtained results, it is predicted that Fe_NGaNNS could be a good candidate for sensing and removing the toxic air pollutant CO gas.