Ti3C2Tx MXene is an emerging two-dimensional transition-metal carbide/nitride with excellent properties of large specific surface and high carrier mobility for room-temperature gas sensing. However, achieving high sensitivity and long-term stability of pristine Ti3C2Tx-based gas sensors remains challenging. SnO2 is a typical semiconductor metal oxide with high reaction activity and stable chemical properties ideal for a dopant that can comprehensively improve sensing performance. Ti3C2Tx and SnO2 are investigated for the first time in this study as functional materials for hybridization and room-temperature detection of the gas insulating medium fluorinated nitrile (C4F7N) with microtoxicity. A Ti3C2Tx-SnO2 nanocomposite sensor exhibits superior sensitivity, high selectivity, strong anti-interference ability, and excellent long-term stability. The enhanced sensing mechanism is ascribed to the synergistic effect between SnO2 and Ti3C2Tx and the strong adsorption ability of SnO2 to C4F7N similar to bait for fish. We also established an actual leakage scene and demonstrated the feasibility of the Ti3C2Tx-SnO2 sensor to provide distribution rules with high sensing efficiency for actual engineering applications. The results of this work can expand the gas sensing application of Ti3C2Tx MXene and provide a reference for maintaining C4F7N-based eco-friendly gas-insulated equipment.
Keywords: Ti3C2Tx-SnO2; density functional theory; eco-friendly insulating gas; gas sensor; leakage detection.