Adsorption of eco-friendly insulating gas C4F7N on PdSe2 monolayer surface: A first-principles study

Heptafluoro-isobutyronitrile (C₄F₇N) is a novel environmentally friendly insulating and arc extinguishing gas utilized as a replacement for SF₆ in gas insulated equipment (GIE). Nevertheless, the potentially hazardous decomposition byproducts of C₄F₇N resulting from sudden equipment failure may jeopardize the normal operation of GIE and the physical well-being of the operator. In this paper, using the first principles study the adsorption behavior of four common C₄F₇N decomposition gases (CF₄, COF₂, CF₃CN, C₂F₅CN) on PdSe₂ monolayer, and explore the adsorption mechanism of PdSe₂ monolayer on C₄F₇N decomposition gas. The results show that the PdSe₂ monolayer interacts with the four decomposition gases by physical adsorption mechanism, in which the PdSe₂ monolayer causes the largest change in electronic properties and maximum work function (0.15 eV) near the Fermi level before and after adsorption of C₂F₅CN, indicating a strong interaction between C₂F₅CN and PdSe₂ monolayer. The sensitivity of PdSe₂ monolayer to C₂F₅CN was up to 68.61 %. Therefore, PdSe₂ monolayer has the potential of selective detection of C₂F₅CN gas sensing materials, and the findings in this paper provide theoretical guidance for the development of PdSe₂ monolayer gas sensing sensors for monitoring C₄F₇N insulation equipment.