Adsorption behavior of Pd-doped SnS2 monolayer upon H2 and C2H2 for dissolved gas analysis in transformer oil

Dissolved gas analysis (DGA) is an effective technique to evaluate the operation status of the power transformer, and to guarantee the safe operation of the power system. Using density functional theory (DFT), we proposed the application of Pd-doped SnS2 (Pd-SnS2) monolayer as a sensing material to detect H-2 and C2H2 in transformer oil. The electronic and geometric structures of Pd-doping behavior on SnS2 were also analyzed to give insight into the physicochemical property of the active surface. The adsorption configuration, density of state (DOS), frontier molecular orbital theory as well as recovery property of the adsorption systems were comprehensively studied to estimate the suitability of our proposed material for sensing application. Our calculations showed that Pd-doping exerts some deformations on the SnS2 monolayer and leads to the narrowed bandgap of such surface. Meanwhile, Pd-SnS2 monolayer has stronger adsorption performance upon C2H2 compared to H-2. And the desirable interaction with C2H2 makes it possible for application of a resistance-type sensor given the good electrical response and recovery property. Our calculations are meaningful to suggest novel sensing material for application in the field of electrical engineering.