First-Principles Calculations for Adsorption of HF, COF₂, and CS₂ on Pt-Doped Single-Walled Carbon Nanotubes

HF, CS₂, and COF₂ are three important decomposition components of the SF₆ gas insulation medium. In this paper, the gas sensitivity of Pt doped on (8, 0) single-walled carbon nanotube (SWCNT) to HF, CS₂, and COF₂ is investigated based on density functional theory. The binding energy, charge transfer, density of states, and frontier molecular orbital theory are discussed. It is found that all processes of HF, CS₂, and COF₂ adsorbed on Pt-SWCNT are exothermic. Pt-SWCNT donated 0.182 electrons to CS₂ molecules during the interaction process but acts as an electron acceptor during adsorption of HF and COF₂ on it. After comprehensive consideration of binding energy and charge transfer, the response of Pt- SWCNT to CS₂ may be the best, and those to HF and COF₂ are almost the same. In addition, after the adsorption of the three kinds of gases on Pt-SWCNT, the order of the conductivity of the Pt-SWCNT material is CS₂ > COF₂ ≈ HF via frontier molecular orbital theory analysis. The Pt-SWCNT material is probably more suitable as a gas sensor for the detection of CS₂ in the application of gas-insulated equipment.