Enhancement of NO2-Sensing Performance at Room Temperature by Graphene-Modified Polythiophene

Hybrids of ethylenediamine-modified reduced graphene oxide (RGO) and polythiophene (PTh) were synthesized successfully by in situ chemical polymerization at room temperature for 2 h and loaded on a flexible PET film to construct a smart sensor. The structure and properties of the hybrids have been characterized by XRD, SEM, TG, UV–vis, and FTIR analysis. The NO 2 -sensing performance of pure PTh- and hybrids-based sensors was examined at room temperature, the results indicate that the hybrid film sensor with 5 wt % RGO not only exhibits high sensitivity to 10 ppm of NO 2 gas which is nearly 4 times higher than that of pure PTh and excellent selectivity but also is flexible, low cost, portable, and wearable. The mechanism of sensing performance enhanced by incorporating graphene into PTh also was discussed, which is attributed to large specific surface of the hybrid and synergetic effects between the components in a hybrid.