Theoretical study on the interaction between SF6 and TiO2(001) surface: A DFT+U study

Abstract

The research on SF₆ degradation and conversion is of great significance for environmental protection. Based on the density functional theory, the adsorption process of SF₆ on the TiO₂(001) and TiO₂(101) surfaces was investigated. The results indicate a strong interaction between SF₆ and the TiO₂ surface. Significant structural changes in the SF₆, such as elongation of the S-F bonds, were observed after adsorption, rendering the SF₆ more prone to decomposition. According to Mulliken charge analysis, electron transfer occurs from the TiO₂ surface to the SF₆, revealing SF₆ as an electron acceptor while TiO₂ acts as an electron donor. Analysis of the density of states confirms a pronounced electronic orbital overlap between the S/F atoms of SF₆ and the Ti/O atoms of TiO₂, and the charge density distribution along the Z-axis further supports this charge transfer process. Additionally, experimental studies have demonstrated that TiO₂ photocatalysis can accelerate the degradation of SF₆ during DBD. This study demonstrates the catalytic potential of TiO₂ in the degradation of SF₆ insulating gas and provides theoretical support for the efficient and harmless treatment of SF₆.