Density functional theory study of adsorption of dissolved gas in transformer oil on Nb -doped SnS2 monolayer

• The adsorption energies of these five gas molecules on their surfaces are increased to different degrees. Among them, the adsorption capacity of C2H2 on Nb/SnS2 is stronger. • The recovery time of C 2 H 2 gas molecules on Nb/SnS 2 is 64.5 s, which makes it a promising gas-sensitive sensor for C 2 H 2 . • The replacement of S atoms by Nb atoms in the doping of SnS 2 improves the gas adsorption performance of the SnS 2 material, and at the same time, its preparation method is close to the reality, and it can be considered to be used as a material for making gas sensors. Based on the density functional theory (DFT), It was found that the adsorption capacity of C 2 H 2 , CO and H 2 on intrinsic SnS 2 was weak, and CH 4 on intrinsic SnS 2 was strong. Meanwhile, the adsorption energies of these five gas molecules on their surfaces are increased to different degrees. Among them, the adsorption capacity of C 2 H 2 on Nb/SnS 2 is stronger, with an adsorption energy of -1.365 eV. From the point of view of the recovery time after adsorption of the gases, at a temperature equal to 498 K, the recovery time of C 2 H 2 gas molecules on Nb/SnS 2 is 64.5 s, which makes it a promising gas-sensitive sensor for C 2 H 2 . The results show that the replacement of S atoms by Nb atoms in the doping of SnS 2 improves the gas adsorption performance of the SnS 2 material, and at the same time, its preparation method is close to the reality, and it can be considered to be used as a material for making gas sensors.