Adsorption and sensing mechanisms of Ni-doped PtTe2 monolayer upon NO2 and O3 in air-insulated switchgears

Under partial discharge, air would be converted into O-3 and NO2 in air-insulated switchgears, therefore, the detection of such two gases can be used to evaluate the operation status of such electrical equipment. In this study, first-principles simulations are implemented to investigate the Ni-doping behavior on the pristine PtTe2 monolayer, and the adsorption and sensing performances of the Ni-doped PtTe2 (Ni-PtTe2) monolayer upon O-3 and NO2 in air-insulated switchgears. The formation energy (E-form) of Ni-doping on the PtTe2 surface was calculated to be -0.55 eV, which indicates the exothermicity and spontaneity of the Ni-doping process. Strong interactions occurred in the O-3 and NO2 systems given the significant adsorption energy (E-ad) of -2.44 and -1.93 eV, respectively. Using the band structure and frontier molecular orbital analysis, the sensing response of the Ni-PtTe2 monolayer upon such two gas species is quite close and large enough for gas detections. Combined with the extremely long recovery time for gas desorption, it is presumed that the Ni-PtTe2 monolayer is a promising one-shot gas sensor for O-3 and NO2 detection with a strong sensing response. This study aims at proposing a novel and promising gas sensing material for the detection of the typical fault gases in air-insulated switchgears, so as to ensure their good operation in the whole power system.