Pd-Decorated WTe₂ Monolayer as a Favorable Sensing Material toward SF₆ Decomposed Species: A DFT Study

Abstract

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 2based materials for gas sensing applications in some other fields.

Effect of Pd/Pt decoration on MoSSe monolayer for CH4 signature through surface adsorption mechanism

“…These results in transition from direct to indirect band gap of 1.27/1.39 eV along Γ → K point. This decrease in band gap of monolayers after Pd/Pt decoration (with PBE functional) also agrees with recently reported results 26 , 40 , 41 . Also, the effect of included spin orbit coupling (SOC) and spin polarizations on the electronic band structures and DOS of pristine and doped MoSSe monolayers is very negligible.…”

Toxic gas sensing performance of arsenene functionalized by single atoms (Ag, Au): a DFT study

“… 24 Recently, Zhang et al proved that the Pd-decorated WTe 2 monolayer shows promising applications as a resistance-type gas sensor for the selective detection of SO 2 and SOF 2 in SF 6 insulation devices. 25 The theoretical calculations uncovered that transition-metal (TM) (Rh, Au, Pd, and Ag)-doped GeTe monolayers not only have superior adsorption properties compared with pure GeTe for vented gases emitted from Lithium-Ion Batteries, e.g. CO 2 , CO, C 2 H 2 , and C 2 H 4 , but also achieve good selectivity to detect and monitor these gases at various temperatures.…”

Gas-sensitive detection of gas pollutants (CO, CO2, N2O) by single-layer Ti-C2N-V : a DFT study

“…Various two-dimensional (2D) materials (graphene, silicene, MoS 2 , etc.) have been applied in the eld of gas sensing due to their high stability, novel structural features, high speci c surface area, volume ratio, low power consumption, strong adsorption capacity [10][11][12][13][14][15]. However, these two-dimensional materials still exhibit some shortcomings, such as the zero band gap value of graphene [16,17], the low structural stability of silicene [18], and the low electron mobility of MoS 2 [19,20], which limit their application in gas sensing.…”