A DFT Calculation of Fluoride-Doped TiO2 Nanotubes for Detecting SF6 Decomposition Components

Gas insulated switchgear (GIS) plays an important role in the transmission and distribution of electric energy. Detecting and analyzing the decomposed components of SF₆ is one of the important methods to realize the on-line monitoring of GIS equipment. In this paper, considering the performance limits of intrinsic TiO₂ nanotube gas sensor, the adsorption process of H₂S, SO₂, SOF₂ and SO₂F₂ on fluoride-doped TiO₂ crystal plane was simulated by the first-principle method. The adsorption mechanism of these SF₆ decomposition components on fluorine-doped TiO₂ crystal plane was analyzed from a micro perspective. Calculation results indicate that the order of adsorption effect of four SF₆ decomposition components on fluoride-doped TiO₂ crystal plane is H₂S > SO₂ > SOF₂ > SO₂F₂. Compared with the adsorption results of intrinsic anatase TiO₂ (101) perfect crystal plane, fluorine doping can obviously enhance the adsorption ability of TiO₂ (101) crystal plane. Fluorine-doped TiO₂ can effectively distinguish and detect the SF₆ decomposition components based on theoretical analysis.