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 approximate to 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.