Low Concentration Ammonia Detection at Room Temperature by Polyaniline (PANI)–Graphene Oxide (GO) Composite

The present study reports very low concentration ammonia detection at room temperature. The sensing material is a composite of polyaniline (PANI) and graphene oxide (GO). The composite material is prepared by ex situ chemical synthesis technique by coating PANI on GO sheets. Prior to the sensing study, the composite material is characterized by XRD, FESEM, Raman, FTIR and TGA. The results of XRD, FESEM, Raman and FTIR suggest the formation of the composite and some interaction between PANI and GO. TGA reveals better thermal stability of the composite over the bare materials. The sensing of the material towards ammonia ( \({\text{NH}}_{3}\) ${\text{NH}}_3$ ) is observed to be excellent at concentration level as low as 5 ppm. The response and recovery times are 21 s and 37 s, respectively. Also, the sensor shows long-term stability.