Trace detection of SF6 gas decomposition component H2S based on Pr6O11-In2O3

Abstract

Sulfur hexafluoride (SF6) from Gas Insulated Switchgear (GIS) will decompose and produce hydrogen sulfide (H2S) in the event of equipment failure. Therefore, the detection of H2S can determine whether the equipment has malfunctioned. Due to the low concentration of the SF6 decomposition product H2S and its application in industrial environments, sensors must have a low detection limit and rapid response time. Considering that the oxides of rare earth elements can improve the sensing characteristics, praseodymium oxide (Pr6O11)-indium oxide (In2O3) was prepared. The impact of Pr6O11 doping on In2O3 was investigated through characterization methods. To validate its feasibility for use in GIS, the best sensor (F3) exhibits good sensing characteristics for H2S in the SF6 and air ambient. The responses to 10 parts per million (ppm) H2S at 190°C were 146.6 in SF6 and 190.8 in air. In SF6 ambient, the F3 sensor demonstrated a low detection limit (50 parts per billion (ppb)). The good sensing characteristics are attributed to the doping of rare earth elements, which induces an increase in the proportion of defect oxygen and accelerate the chemical reaction. The sensing characteristics of the material can be attributed to the doping of Pr6O11 and the electronic effect. This study provides a novel approach for detecting H2S generated from SF6 decomposition.