Adsorption and gas-sensing properties of C2H4, CH4, H2, H2O on metal oxides (CuO, NiO) modified SnS2 monolayer: A DFT study
Ying Chen, Yingang Gui, Xianping Chen
Abstract
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 SnS 2 monolayer were exploited to reveal their gas-sensing properties to the typical oil dissolved gases (C 2 H 4 , CH 4 , H 2 ) and H 2 O. 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-SnS 2 the adsorption capacity is ranked as: C 2 H 4 > H 2 O > H 2 > CH 4 . For NiO-SnS 2 the adsorption capacity is ranked as: H 2 O > C 2 H 4 > H 2 > CH 4 . By contrast, CuO-SnS 2 shows higher superiority towards C 2 H 4 adsorption, while the adsorption energy of CH 4 ,H 2 and H 2 O on NiO-SnS 2 is more prominent than that of CuO-SnS 2 . Considering the ameliorative electronic properties and appropriate adsorption energy, NiO-SnS 2 can be a potential candidate sensor for C 2 H 4 .