Effective Room-Temperature Ammonia-Sensitive Composite Sensor Based on Graphene Nanoplates and PANI

The graphene nanoplate (GN)-polyaniline (PANI) composite was developed via in-situ polymerization method and simultaneously assembled on interdigital electrodes (IDEs) at low temperature for ammonia (NH3) detection. The assembled composite sensor showed excellent sensing performance toward different concentrations of NH3, 1.5 of response value and 123 s/204 s for the response/recovery time to 15 ppm NH3. Meanwhile, an interesting supersaturation phenomenon was observed at high concentration of NH3. A reasonable speculation was proposed for this special sensing behavior and the mechanism for enhanced sensing properties was also analyzed