The sensitive characteristics analysis on adsorbent-doped carbon nanotube sensors for detecting H2S

Although Gas Insulated Switchgear (hereinafter referred to as GIS) equipment has the very high operation reliability, the internal inevitable defects of GIS could cause partial discharge (short for PD). SF₆ gas decomposition occurs because of the energy which PD produced. The analysis of SF₆ gas components in GIS is of great significance in the diagnosis and assessment of the operating status of GIS. As an important characteristic gas, the variation detection in the concentration of H₂S is significant to judge the insulation level of SF₆ gas. There are a number of gas sensors using carbon nanotubes. Unfortunately, their applications are greatly limited by their low intrinsic sensitivity. In this paper, we propose an adsorbent-doped carbon nanotubes gas sensor to make an improvement in detecting the concentration of H₂S. The preparation and test method of the developed sensor was introduced. Meanwhile, the sensor response was conducted using the gas test device. We perform experiments and the results show that, compared to intrinsic carbon nanotubes gas sensor, the gas sensor featuring adsorbent-doped carbon nanotubes has a great deal higher sensitivity and responsiveness to H₂S. In other words, the developed sensor has a capability of detecting the low concentration H₂S. Therefore, it indicates that the doped sensor can improve the minimum detectable concentration of H₂S and has great potential in H₂S detection. Resistance change rate of H₂S increased to 23.69% from 12.9%. Meanwhile, the sensor has good repeatability and stability.