A room temperature NH3 gas sensor based on a quartz crystal microbalance coated with a rGO–SnO2 composite film

摘要

Novel QCM NH3 gas sensors made of reduced graphene oxide–SnO2 (rGO–SnO2) composite films were fabricated using a one-pot technique, which is a fast and easy fabrication route that is useful for practical applications. The surface morphology and composition of the rGO–SnO2 composite films were analyzed using Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy coupled with energy-dispersive X-ray elemental mapping and transmission electron microscopy. On the basis of the microstructural observations, SnO2 connected to rGO sheets and naked rGO sheets were observed on the surface of the rGO–SnO2 composite films. The effects of the amount of added rGO sheets on the enhancement of the NH3 gas sensing properties of the rGO–SnO2 composite films were studied. The analysis of the adsorption dynamics (association constant) confirmed the higher sensitivity of the QCM NH3 gas sensor based on the rGO–SnO2 composite film than that of the sensor with the pristine SnO2 film.