DFT Study of SO₂F₂ and SOF₂ Adsorption on (6,0) AlN Nanotube: Adsorbent and Gas Detector Toward SF₆ Decomposition Products

This study investigates the adsorption effects of SO₂F₂ and SOF₂ gases on the electronic properties of a (6,0) aluminum nitride (AlN) nanotube using density functional theory (DFT). Key calculations include the optimal adsorption configuration, adsorption energy, band structure, density of states (DOSs), and charge transfer. The results indicate that both gases chemically adsorb onto the AlN nanotube surface. Given the stable adsorption of SO₂F₂ and SOF₂ on the AlN nanotube, it is concluded that AlN nanotubes can serve as effective adsorbents for these decomposition products, potentially reducing insulation degradation in sulfur hexafluoride (SF₆)-insulated environments. Other key findings include: 1) following SO₂F₂ adsorption, the nanotube retains its p-type nature, although the Fermi level shifts up by 0.69 eV, indicating reduced conductivity; 2) SOF₂ adsorption transforms the nanotube from a p-type to a weak n-type semiconductor; and 3) the work function of the nanotube decreases from 4.8 to 4.1 eV and 3.9 eV following the adsorption of SO₂F₂ and SOF₂, respectively. Based on the observed changes in electrical conductivity, work function, and semiconductor behavior, the study also proposes practical designs for resistive, Schottky, and thermoelectric power sensors. In conclusion, the AlN nanotube is identified as a promising candidate for sensor development and adsorbent applications targeting SO₂F₂ and SOF₂ gases.