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.