High Sensitivity, Humidity-Independent, Flexible NO₂ and NH₃ Gas Sensors Based on SnS₂ Hybrid Functional Graphene Ink

Abstract

Here, a high sensitivity gas sensing ink based on sulfonated rGO (S-rGO) decorated with SnS₂ is synthesized for room temperature NO₂ and NH₃ detection. This sensing ink demonstrated an excellent sensitivity to ppb-level NO₂ (17% response to 125 ppb) and sub-ppm-level NH₃ (11% response to 1 ppm). The unique absorption properties of SnS₂ improve the sensitivity of S-rGO 4.2 and 55 times to NO₂ and NH₃, respectively. Besides, the superhydrophobicity of the SnS₂ endows the sensor with exceptional immunity to high relative humidity (RH). Furthermore, the sensors exhibit negligible degradation to NO₂ and less than 15% degradation to NH₃ in a wide range of RH from 30 (ambient humidity) to 90%. More importantly, the obtained full-written ink can be applied to common substrates, such as glass, clothes, and paper, and maintain excellent performance after being bent and twisted by 180°.