Novel SnO2/PAni nanocomposites for selective detection of ammonia at room temperature

The present study aims to investigate a new method of SnO2/polyaniline (PAni) nanocomposite sensor fabri-cation for detection of ammonia at different temperatures including the room one. The fabrication of composite is performed by synthesis of PAni according to oxidative polymerization. Then the SnO2/PAni hybrid nano-composites containing different percentages of polymer were fabricated by a deposition-precipitation method in presence of SnCl4 solution. The produced powders were characterized by XRD, BET, FTIR, Raman, TGA and FESEM tests. By increasing PAni contents of the nanocomposites, SnO2 crystallite sizes decrease, the surface area increases, and thermal stability improves. The sensing behavior of SnO2/0-30 wt% PAni in presence of 100-500 ppm ammonia was measured. The SnO2/8 wt% PAni shows the best sensitivity, where the response of sensor for 100 ppm NH3 at room temperature is about 187 %. Optimum heteronucleation and decoration of SnO2 on PAni surface enhances the response. Moreover, the sensor is selective in presence of interfering gases including CO, ethanol, methane, toluene and trichloroethylene.