Adsorption of CO, F2, and NO2 on stanene nanoribbons: Optoelectronic properties and sensing applications

The structural and optoelectronic properties of pristine stanene nanoribbons and their modifications upon adsorption of CO, F2, and NO2 gas molecules were systematically investigated using density functional theory. Pristine SnNRs were identified as semiconductors with an intrinsic band gap of approximately 0.308 eV. Notably, the adsorption of F2 and NO2 induced a semiconductor-to-metal transition, whereas CO-adsorbed SnNRs retained semiconducting behavior with a band gap of 0.288 eV. Magnetic analysis revealed a transition from a nonmagnetic ground state in pristine SnNRs to a magnetic state upon gas adsorption, with magnetic moments of 2.624 mu B, and 1.099 mu B for F2 and NO2, respectively. The underlying adsorption mechanisms were elucidated through detailed investigations of multi-orbital hybridization, charge density redistribution, and optical properties, including the dielectric function, absorption coefficient, and joint density of states. These findings underscore the potential of SnNRs for nanoscale optoelectronic applications and as gas sensors for CO, F2, and NO2.