Fabrication of polypyrrole/tin oxide/graphene nanoribbon ternary nanocomposite and its high-performance ammonia gas sensing at room temperature

In this study, the polypyrrole (PPy)/tin oxide (SnO₂)/graphene nanoribbon (GNR) ternary nanocomposites are successfully synthesized using in situ chemical oxidative polymerization. In doing so, the SnO₂ nanoparticles fabricated using a solvothermal reaction are coated on the surface of the GNR. The gas sensing performances of nanocomposites at room temperature are estimated by a homemade dynamic test system, equipped with a simultaneous resistance measurement platform. The response value of the PPy/SnO₂/GNR sensor containing 3-wt% SnO₂ nanoparticles with an exposure of 1-ppm NH₃ is 92.7, which is roughly three times greater than that of a pure PPy sensor. This composite sensor can sensitively detect the NH₃ between concentrations of 0.6 and 2 ppm at room temperature. The PPy/SnO₂/GNR sensor also has higher repeatability and selectivity when exposed to 1- and 2-ppm NH₃ at room temperature than existing sensor. Due to the outstanding repeatability and selectivity, it is evident that the PPy/SnO₂/GNR nanocomposite sensor is a promising gas sensing material for the detection of the hepatic or kidney disease in human breath.