Fabrication of multilayer SnO2–ZnO–PPy sensor for ammonia gas detection

The sensitivity of SnO 2 –ZnO composites in multilayer with PPy and Al 2 O 3 has been studied. Composites of SnO 2 –ZnO have been prepared and multilayer sensor has been fabricated using screen printing technique with Al 2 O 3 as substrate on glass plate and PPy in multilayer with SnO 2 –ZnO. The morphologies of composites of SnO 2 –ZnO and PPy have been studied by scanning electron microscopy and crystallite size by X-ray diffraction. Sensitivity has been found to be more for 70SnO 2 :30ZnO/PPy/Al 2 O 3 multilayer sensor, which is supported by scanning electron microscopy and X-ray diffraction studies. It has been found that with the increase in concentration of NH 3 gas, the response of multilayer sensor increases.