Highly sensitive NO2 gas sensors based on hexagonal SnS2 nanoplates operating at room temperature.

ABSTRACT

While continuously developing high-performance chemoresistive gas sensors, reducing device power consumption is not negligible. One of the most efficient ways is to enable gas sensors to work close to room temperature. In this work, we present a gas sensor based on hexagonal tin disulfide (SnS2) nanoplates for sensitive and reversible NO2 sensing at room temperature. Two-dimensional SnS2 nanoplates are synthesized via a facile hydrothermal method using Triton X-100 as a surfactant. The sensor exhibits a high response of 15.6 for 50 ppm NO2 with an experimental limit of detection of 50 ppb at room temperature. Besides, excellent linearity, outstanding selectivity, and reliable long-term stability within 40 d are also demonstrated during the experiment process. The sensing mechanism of this sensor could be explained as the physisorption and charge transfer between NO2 molecules and SnS2 nanoplates, which make it possible for the sensor to work at such a low operating temperature. Our research resulted in a SnS2 nanoplate-based sensor that may pave a new way for effective NO2 detection in the future.