Nb-doped PtS2 monolayer for detection of C2H2 and C2H4 in on-load tap-changer of the oil-immersed transformers: A first-principles study

• Nb-doping behaviors on PtS 2 monolayer is studied. • Expound the electronic property of Nb-PtS 2 monolayer upon C 2 H 2 and C 2 H 4 adsorptions. • Analyze the sensing mechanism and recovery time for gas detections. First-principles calculations are conducted to investigate the Nb-doped PtS 2 (Nb-PtS 2 ) monolayer for sensing C 2 H 2 and C 2 H 4 in the on-load tap-changer of the oil-immersed transformers. The adsorptions of two gases on the Nb-PtS 2 monolayer are verified as chemisorption with adsorption energies of −2.47 and −1.0.91 eV, as confirmed by Hirshfeld analysis, charge density difference and orbital density of state. The band structure indicates the good sensing response of 1206.7% and −4717.4%, for C 2 H 2 and C 2 H 4 detections, suggesting its strong potential as a resistance-type gas sensor for their detections. This work paves the ways to explore novel PtS 2 -based gas sensor effectively.