High sensitive and selective flexible H2S gas sensors based on Cu nanoparticle decorated SWCNTs

• A flexible H2S gas sensor by incorporating SWCNTs decorated with Cu NPs as sensitive material.
• A fast response and a recovery time of ∼10 s and ∼15 s, respectively, are obtained for 5 ppm gas.
• Response of flexible sensors upon exposure to 20 ppm H2S is acquired with a bending radius of 7.8 mm.
• Ab initio simulations are performed to explore the underlying H2S sensing mechanism of sensors.

We present sensitive flexible H2S gas sensors operating at room temperature based on Cu-SWCNTs. SWCNTs are decorated with metallic cluster of Cu nanoparticles (NPs) by employing a reduction chemical process and are spin coated on a polyethylene terephthalate (PET) flexible substrate for achieving facile and cheap sensors. Cu-SWCNTs-based sensors show remarkable responses upon exposure to various concentrations of H2S gas in the range of 5 ppm to 150 ppm. A fast response time and a recovery time of ∼10 s and ∼15 s, respectively, are obtained for 5 ppm of H2S. Resistance modulation – without any significant degradation – is observed for bending radii larger than 4 mm. The sensors show reproducible response upon exposure to larger than 20 ppm of H2S and bending radii larger than 7.8 mm. Ab initio simulations are performed to explore the underlying H2S sensing mechanism of Cu-SWCNTs. In agreement with our experiments, theoretical analyses indicated that the decoration of SWCNTs with Cu atoms enhances the sensitivity of SWCNTs for H2S gas detection.