Pt-doped TiO2-based sensors for detecting SF6 decomposition components

Detection of partial discharge and analysis of SF₆ gas components in gas-insulated switchgear are important for diagnosis and operating state assessment of power equipment. The gas-sensing properties of the existing TiO2 nanotube (TiO₂NT) array-based and the Pt-doped TiO2NT-based sensors were investigated for the components of SF6 decomposition. Four sensors with different amounts of Pt-doped TiO2NTs are prepared using constant current method. The sensing responses of the sensors to the main decomposition gases of SF6 (i.e., SO₂, SOF₂ and SO₂F₂) are examined, and the gas-sensing characteristic curves are comparatively analyzed. In addition, the mechanisms of the sensitive responses are discussed. Results show that a higher doping amount of Pt benefits the detection of SO₂F₂, whereas a lower doping amount is suitable for detecting SO₂, which is similar with the capabilities of the intrinsic TiO₂NT sensor. Moreover, the working temperature of the Pt-doped TiO₂NT sensor is lower than that of the intrinsic TiO₂NT sensor.