Gas sensing properties of a Cu-doped PANI nanocomposite towards ammonia

Abstract

This study exhibits the use of nanocomposite films containing copper nanoparticles at various concentrations to selectively detect ammonia gas. Using the chemical oxidative polymerization method, the samples were submerged in a PANI matrix and then subjected to varying concentrations of NH₃ at room temperature to investigate their gas-sensing capabilities. For 100 ppm of NH₃ gas, a gas sensing response of 51% was achieved for PANI loaded with 0.2 g of Cu nanoparticles (PANI@Cu1). Combining PANI@Cu with nanocomposite porosity augmentation improves the resistance, which was already robust before NH₃ deprotonation. An extraordinarily high level of selectivity towards NH₃ gas at ambient temperature was seen in films with a 2 g loading of Cu embedded in a PANI matrix (PANI@Cu5), among the many compositions that were tested. With a recovery time of less than 20 seconds, the resultant sensor responded with 62% accuracy at 300 ppm. Aside from NH₃ gas, the designed sensor is less selective for ethanol, CO, CO₂, and H₂S.