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

[Display omitted] •Nb-doping behaviors on PtS2 monolayer is studied.•Expound the electronic property of Nb-PtS2 monolayer upon C2H2 and C2H4 adsorptions.•Analyze the sensing mechanism and recovery time for gas detections. First-principles calculations are conducted to investigate the Nb-doped PtS2 (Nb-PtS2) monolayer for sensing C2H2 and C2H4 in the on-load tap-changer of the oil-immersed transformers. The adsorptions of two gases on the Nb-PtS2 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 C2H2 and C2H4 detections, suggesting its strong potential as a resistance-type gas sensor for their detections. This work paves the ways to explore novel PtS2-based gas sensor effectively.