Ag‐doped Ti3C2Tx sensor: A promising candidate for low‐concentration H2S gas sensing

Abstract Trace hydrogen sulphide (H2S) could reflect the severity of insulation faults in gas‐insulated switchgear (GIS), therefore, accurate and fast detection of low‐concentration H2S is important for on‐line monitoring, fault diagnosis, and state evaluation in GIS. Ag‐Ti3C2Tx chemiresistive‐type sensors were fabricated via drop‐coating with self‐reduction synthesised Ag‐doped Ti3C2Tx. The as‐prepared sensors exhibited an excellent sensitivity and selectivity to H2S with an extremely low detection of limit of 18.57 parts per billion (ppb) at 25°C (room temperature). The response of Ag‐Ti3C2Tx sensor to 10 parts per million (ppm) H2S was enhanced ∼12 times than that of the pristine Ti3C2Tx sensor. The compositing of Ti3C2Tx with Ag nanoparticles (NPs) enabled the fast response/recovery time for H2S detection. Further analysis found that the enhanced H2S sensing performances could be attributed to chemical sensitisation, adsorbed oxygen species regulation and high Brunauer–Emmett–Teller (BET) surface area. This study paves the way for Ag‐Ti3C2Tx as room‐temperature sensing materials to detect low‐concentration H2S in GIS.