Room Temperature Ammonia Gas Sensor Based on Polyacrylonitrile/Silver@Polyaniline Nanofibers

Polyacrylonitrile/ silver@polyaniline (PAN/Ag@PANI) composite nanofibers were prepared via electrospinning and photo-assisted technique. PAN nanofibers fabricated using electrospinning acted as templates, and then Ag@PANI compound were synthesized by in-situ polymerization method assisted with photo and grew onto the surface of PAN nanofibers. The obtained PAN/Ag@PANI composite nanofibers were tested as ammonia sensors at room temperature towards low detection range (400 ppb-200 ppm), and their response values were compared to that of PAN/PANI composite nanofibers produced with the same technique. The results show that the PAN/Ag@PANI composite nanofibers presented higher response values, ideal recovery time, repeatability and selectivity. But with the increase of Ag in the composite nanofibers, the response values did not improve, because Ag acted as a dopant when its content was not very high, and if there was too much Ag existed in the sensors, the electrical conductivity depended more on the silver.