Facile preparation of polypyrrole-reduced graphene oxide hybrid for enhancing NH₃ sensing at room temperature

Polypyrrole (PPy)-reduced graphene oxide (rGO) hybrid was successfully synthesized by a facile in situ polymerization. The as-synthesized PPy nanoparticles with diameter of ca. 80 nm were uniformly distributed on the surface of the rGO sheets to prepare the hybrid of PPy/rGO. Then the pure PPy and their hybrids were loaded on the substrate of flexible polyethylene terephthalate (PET) film to construct a thin film NH₃ sensor, which has the advantages of being flexible, economical, portable and able to operable at room temperature (RT). The gas-sensing results reveal that the 5 wt% rGO-PPy hybrid based sensor not only exhibits the highest response to 10 ppm NH₃, which is 2.5 times higher than that of pure PPy, but also excellent selectivity to some of VOCs. The enhancement of gas-sensing properties may be attributed to the π-π stacking and H-bonding formation between PPy and rGO, larger surface accessibility and fast transport of carriers.