Temperature dependent selective detection of ethanol and methanol using MoS2/TiO2 composite

Volatile organic compounds may cause blindness, organ failure and serve as tracer for air quality controls or environmental monitoring. However, their detection at lower concentration and discrimination between compounds belonging to the same class has remained a challenging task. Methanol and ethanol, for instance, are difficult to distinguish from each other using chemiresistive sensors. Here, we report a highly sensitive, and stable sensor based on the MoS2/TiO2 composite for temperature-dependent selective detection of ethanol and methanol. The device has shown selective methanol (5 ppm) and ethanol (1 ppm) detection with superior signal-to-noise ratio at 240 and 300 °C, respectively. Further, the composite based sensor displayed excellent sensitivity/stability, repeatability and small change in relative response when humidity was changed between 20% and 90%. Furthermore, the long-term stability of the sensor was evident from the stable response curves even after 2 months. The results suggest that composites based on TiO2/MoS2 nanosheets can be engineered for selective detection of chemically similar molecules and may serve as a potential candidate in environmental monitoring and biomedical diagnosis.