Room temperature gas sensors for NH3 detection based on SnO2 films and lamellar-structured Ti3C2Tx MXene heterojunction nanocomposites

Efficient and accurate detection of ammonia (NH3) by gas sensors at room temperature holds great practical value and significance in industrial production and environmental protection. In this work, we designed SnO2/Ti3C2Tx heterojunction nanocomposites via a facile RF magnetron sputtering technique. Benefitting from the surface porosity and few lamellar-structured of the composites, as well as the construction of heterojunctions between SnO2 and Ti3C2Tx, the SnO2/Ti3C2Tx sensor demonstrated a response of up to 13.35 % towards 50 ppm NH3 at room temperature, which was 3.5 times higher than the Ti3C2Tx-based sensor. Meanwhile, the response/recovery time was reduced to 24.9/86.5 s. In addition, the SnO2/Ti3C2Tx sensor exhibited good selectivity, repeatability, and long-term stability. This work should provide an effective strategy for the design of high-performance NH3 gas sensors at room temperature.