Highly selectivity isopropanol sensor based on SnO₂ nanotubes at low operating temperature

The design of an isopropanol gas sensor with excellent response and trace detection capability is of significant importance for environmental monitoring and human health. Herein, a simple template method was developed to fabricate uniform SnO₂ nanotubes by using MnO₂ nanowires as sacrificial templates. Meanwhile, the gas sensing properties of SnO₂ nanotubes prepared with different molar additions of SnSO₄ were systematically evaluated and compared. The measurement results indicated that the prepared SnO₂ nanotubes (SnO₂-1) possess relatively superior gas sensing performances when the molar addition of SnSO₄ is 1 mmol. The SnO₂-1 sensors displayed a high gas sensing response value (42.3), fast response/recovery times (6.3/8.6 s), superior selectivity, and good stability for 50 ppm isopropanol at a relatively low operating temperature (120 °C). Specially, the sensor can detect even isopropanol down to 0.5 ppm with a sensitive response (2.0). These remarkable gas sensing properties are mainly attributed to the tubular nanostructures possessing high specific surface area and abundant pores, providing a promising strategy for designing isopropanol gas sensors with high practicality.