TiO2–Doped GeSe Monolayer: A highly selective gas sensor for SF6 decomposed species detection based on DFT method

Abstract The detection of SF6 decomposition species has been a crucial method of fault diagnosis for insulation equipment. Faced with problems of poor selectivity, low sensitivity and non-recyclability of existing nano-gas sensors, TiO2-doped GeSe monolayer is proposed. The doping of TiO2 nanoparticle greatly improves the conductivity of GeSe monolayer and the selective for SF6 decomposition species, SO2 > H2S > SOF2 > SO2F2. Moreover, electron transfer of SF6 is further inhibited. When gases are adsorbed, the reduction of the difficulty of electron transition ensures the high sensitivity detection in practical application, especially SO2. Ideal adsorption energies ensure that TiO2-GeSe monolayer has excellent response and recovery ability, which theoretically solves the industrial problem of recycling. In addition, compared with pure GeSe and other normal 2D materials, TiO2-GeSe exhibits excellent sensing detection advantages. This study provides a theoretical foundation for resistive chemical sensors used in industrial insulation equipment.