Adsorption and Sensing of SF6 Decomposition Products by a Pd-Doped MoTe2 Monolayer: A First-Principles Study

The detection of sulfur hexafluoride (SF6)decompositioncomponents has become one of the best ways to diagnose early latentinsulation faults in gas-insulated equipment, which can effectivelyprevent sudden accidents by identifying such faults. In this paper,we by first-principles theory investigated the adsorption and sensingbehaviors of four typical SF6 decomposition components(H2S, SO2, SOF2, and SO2F2) on the pristine Pd-doped MoTe2 monolayer.The adsorption energy, work function, recovery time, charge densitydifference, density of state, and band structure of the adsorptionstructures are obtained as well as analyzed. The results indicatethat the Pd dopant prefers to be trapped at the T-Mo site,with a binding energy of -2.25 eV. The Pd-MoTe2 chemisorbsthe remaining gases except SO(2)xF(2), with theadsorption capacity ranking as SOF2 > SO2 >H2S. The adsorption of gas molecules reduces the bandgapof Pd-MoTe2, thereby increasing conductivity. On the otherhand, the recovery time of the Pd-MoTe2 monolayer materialat a temperature of 398 K demonstrates its excellent gas desorptionperformance toward four decomposition gases. The research resultsprovide a theoretical basis for Pd-MoTe2 to detect SF6 decomposition components, thus, promoting the stable operationof the power system.