Sensitive detection of ammonia by reduced graphene oxide/polypyrrole nanocomposites

The polypyrrole (PPy) and its composite with reduced graphene oxide (rGO) are prepared by drop cast in-situ oxidative polymerization method. The fabricated thin film sensors are used for ammonia (NH3) gas sensing and are characterized by TEM, FEG-SEM, FT-IR, X-Ray diffraction and UV-vis methods. The PPy/rGO thin film sensors show very good sensing response to ammonia gas and are able to sense ammonia at 3 ppm. Sensitivity of these composites increases with increasing concentration of ammonia gas, and starts saturating at higher concentration. Sensitivity of PPy/rGO based sensor is nearly 3 times more than the PPy thin film sensor. It has been found that the sensors recovered fully after heating up to similar to 50 degrees C. (C) 2015 Elsevier B.V. All rights reserved.