Highly Sensitive and Selective PANI/Ag Nanocomposites-Based Gas Sensors for Room-Temperature NH3 Detection

Highly sensitive gas sensors for detection of hazardous gases at room temperature is a critical research area. This study presents the fabrication of NH3 gas sensors based on polyaniline (PANI) and Polyaniline/silver nanocomposites (PANI/Ag NCs). PANI and Ag NPs were prepared by chemical oxidation and polyol methods, while PANI/Ag NCs were prepared using an ultrasonic-assisted method. XRD analysis confirmed the crystallinity of Ag NPs and the amorphous nature of PANI. SEM images revealed the porous structure of PANI and the uniform distribution of Ag NPs within the PANI matrix. UV–Vis analysis displayed the characteristic absorbance peaks and FTIR analysis confirmed the purity of the synthesized materials. The PANI/Ag (80/20) NC sensor notably displayed significantly improved gas-sensing properties over pristine PANI in terms of higher capacitive and resistive responses, superior sensitivity up to 1047.2%, and faster response/recovery times of 20/6 sec at 36 ppm. The enhanced performance would be ascribed to the enhanced surface area with the incorporation of AgNPs and better electron mobility. The results suggest that PANI/Ag NC-based sensors have excellent potential for efficient room-temperature gas detection.