Visual chemiresistive dual-mode sensing platform based on SnS2/Ti3C2 MXene Schottky junction for acetone detection at room temperature

In the work, a SnS2/Ti3C2 MXene composite was assembled through electrostatic interaction and aerosol -deposited onto flexible substrates for gas sensing. After that, a visual chemiresistive dual-mode sensing plat-form was constructed by integrating a sensing electrode and a light emitting diode (LED) into a circuit, which can simultaneously produce resistance and light intensity signals towards gas molecules. Due to the synergistic effect of SnS2 and Ti3C2 MXene, the sensing platform exhibited excellent response toward acetone at room temperature. Specifically, the chemiresistor showed a decent corresponding relationship for acetone in the concentration range of 1-100 ppm with extrapolated limit of detection of 5.5 ppb. The response toward 50-ppm acetone was 29.8%, and the response and recovery time was 88 s and 356 s, respectively. The selectivity of acetone is higher than 1.4 (response ratio at 50 ppm) over typical confounders including ethanol, methanol, toluene, octane, benzene and hexane. The light signals from LEDs were collected simultaneously by a wireless camera, and analyzed via an image processing software in a smartphone. A favorable correspondence was presented between Euclidean distance and acetone concentration (1-100 ppm). The Euclidean distance was 109 for 50 ppm acetone. The admirable optical-electrical detection ability of the sensing platform provides a new idea and reference for constructing multi-mode sensors with low-power consumption.