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

Abstract

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 5ppm to 150ppm. A fast response time and a recovery time of ∼10s and ∼15s, respectively, are obtained for 5ppm of H2S. Resistance modulation – without any significant degradation – is observed for bending radii larger than 4mm. The sensors show reproducible response upon exposure to larger than 20ppm of H2S and bending radii larger than 7.8mm. 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.