Pd-Decorated WTe 2 Monolayer as a Favorable Sensing Material toward SF 6 Decomposed Species: A DFT Study.

Based on density functional theory, this work first investigates the Pd-decorating property on the pristine WTe ₂ monolayer and then simulates the adsorption performance of a Pd-decorated WTe ₂ (Pd-WTe ₂ ) monolayer on SO ₂ and SOF ₂ molecules, in order to explore its sensing potential for SF ₆ decomposed species. It is found that the Pd atom can be stably anchored on the top of the W atom of the WTe ₂ monolayer with a binding energy of -2.43 eV. The Pd-WTe ₂ monolayer performs chemisorption on SO ₂ and SOF ₂ , with adsorption energies of -1.36 and -1.17 eV, respectively. The analyses of the band structure and density of states reveal the deformed electronic property of the WTe ₂ monolayer by Pd-decoration, as well as that of the Pd-WTe ₂ monolayer by gas adsorption. The bandgap of the Pd-Wte ₂ monolayer is increased by 1.6% in the SO ₂ system and is decreased by -3.9% in the SOF ₂ system, accounting for the sensing response of 42.0 and -56.7% for the detection of two gases. Moreover, the changed work function (WF) in two gas systems in comparison with that of the pristine Pd-WTe ₂ monolayer suggests its potential as a WF-based gas sensor for sensing two gases as well. This paper uncovers the gas sensing potential of the Pd-WTe ₂ monolayer to evaluate the operation status of SF ₆ insulation devices, which also illustrates the strong potential of WTe ₂ -based materials for gas sensing applications in some other fields.
Competing Interests: The authors declare no competing financial interest.
(© 2023 The Authors. Published by American Chemical Society.)