Adsorption Behavior of Pd-Doped PtS₂ Monolayer Upon SF₆ Decomposed Species and the Effect of Applied Electric Field

PtS
₂
monolayer with desirable gas sensing property is suggested in this work based on the first-principles theory for detection of three SF
₆
decomposed species, in order to evaluate the operation status of the SF
₆
insulation devices in power systems, and Pd-doping is proposed to enhance the sensing performance of PtS
₂
monolayer. Results indicate that Pd dopant is stably anchored on the
$\text{T}_{\rm Pt}$
site of the PtS
₂
surface with a
${E}_{\rm b}$
of −2.34 eV. The adsorption performance of the Pd-doped PtS
₂
(Pd-PtS
₂
) monolayer upon three SF
₆
decomposed species is in order as SO
₂
> SOF
₂
> SO
₂
F
₂
, with
${E}_{\rm ad}$
of −1.04, −0.84 and −0.19 eV, respectively. Thus, chemisorption is identified for the SO
₂
and SOF
₂
systems with remarkable increase of bandgap for the Pd-PtS
₂
monolayer by 0.044 and 0.041 eV, respectively, while physisorption is identified for the SO
₂
F
₂
system with relatively smaller increase of bandgap by 0.029 eV. Moreover, an applied electric field can effectively modulate the charge-transfer for the gas adsorption systems, which manifests the strong potential of Pd-PtS
₂
monolayer as a field-effect transistor gas sensor for detection of SO
₂
, SOF
₂
and SO
₂
F
₂
with high sensing response. Moreover, I-V curves in Pd-PtS
₂
system with and without gas adsorption are also analyzed to verify the above findings. Our theoretical report is meaningful to explore novel sensing materials for application in the field of electrical engineering and to guarantee the good operation of power systems.