Adsorption and gas-sensing properties of C2H4 , CH4, H2, H2O on metal oxides (CuO, NiO) modified SnS2 monolayer: A DFT study

Detection of oil dissolved gases is of great significance to diagnose the diverse insulation faults in oil-immersed transformers. Therefore, the Metal oxides (CuO, NiO) doped SnS2 monolayer were exploited to reveal their gas-sensing properties to the typical oil dissolved gases (C2H4, CH4, H-2) and H2O. Based on density functional theory calculations, the most stable modified substrate and adsorption structures were selected according to adsorption energy and geometry optimization. In addition, the gas-sensing mechanisms were obtained through the analysis of the adsorption structure, molecular orbit, charge transfer, total density of states and projected density of states. For gases adsorption on CuO-SnS2 the adsorption capacity is ranked as: C2H4 > H2O > H-2 > CH4. For NiO-SnS2 the adsorption capacity is ranked as: H2O > C2H4 > H-2 > CH4. By contrast, CuO-SnS2 shows higher superiority towards C2H4 adsorption, while the adsorption energy of CH4, H-2 and H2O on NiO-SnS2 is more prominent than that of CuO-SnS2. Considering the ameliorative electronic properties and appropriate adsorption energy, NiO-SnS2 can be a potential candidate sensor for C2H4.

Automated summary

In the study of the gas-sensing properties of metal oxides (CuO, NiO) doped SnS2 monolayer to typical oil dissolved gases, NiO-SnS2 showed better adsorption capacity for C2H4, making it a potential candidate sensor for C2H4.