First-Principles Calculations for Adsorption of HF, COF, and CS on Pt-Doped Single-Walled Carbon Nanotubes.

HF, CS, and COF are three important decomposition components of the SF gas insulation medium. In this paper, the gas sensitivity of Pt doped on (8, 0) single-walled carbon nanotube (SWCNT) to HF, CS, and COF 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, CS, and COF adsorbed on Pt-SWCNT are exothermic. Pt-SWCNT donated 0.182 electrons to CS molecules during the interaction process but acts as an electron acceptor during adsorption of HF and COF on it. After comprehensive consideration of binding energy and charge transfer, the response of Pt- SWCNT to CS may be the best, and those to HF and COF 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 CS > COF ≈ HF via frontier molecular orbital theory analysis. The Pt-SWCNT material is probably more suitable as a gas sensor for the detection of CS in the application of gas-insulated equipment.