Adsorption performance of M-doped (M = Ti and Cr) gallium nitride nanosheets towards SO(2) and NO(2): a DFT-D calculation

The structure, adsorption characteristics, electronic properties, and charge transfer of SO(2) and NO(2) molecules on metal-doped gallium nitride nanosheets (M-GaNNSs; M = Ti and Cr) were scrutinized at the Grimme-corrected PBE/double numerical plus polarization (DNP) level of theory. Two types, M(Ga)-GaNNSs and M(N)-GaNNSs, of doped nanostructures were found. The M(Ga) sites are more stable than the M(N) sites. The results showed that adsorption of SO(2) and NO(2) molecules on Ti(Ga,N)-GaNNSs is energetically more favorable than the corresponding Cr(Ga,N)-GaNNSs. The stability order of complexes is energetically predicted to be as NO(2)–Ti(Ga)-GaNNS > NO(2)–Ti(N)-GaNNS > SO(2)–Ti(Ga)-GaNNS > NO(2)–Cr(N)-GaNNS > SO(2)–Ti(N)-GaNNS > NO(2)–Cr(Ga)-GaNNS > SO(2)–Cr(N)-GaNNS > SO(2)–Cr(Ga)-GaNNS. The electron population analysis shows that charge is transferred from M(Ga,N)-GaNNSs to the adsorbed gases. The Ti(Ga)-GaNNS is more sensitive than the other doped nanostructures to NO(2) and SO(2) gases. It is estimated that the sensitivity of Ti(Ga)-GaNNS to NO(2) gas is more than to SO(2) gas.