Synthesis, characterization and comparative gas sensing study of ZnO–GO and ZnO–rGO compounds

In this work, we prepare composites of ZnO–GO and ZnO–rGO through an economic and facile route and comparatively study their gas sensitivity towards ethanol. The morphological, compositional and structural properties of the prepared composites are investigated using scanning electron microscopy (SEM), energy–dispersive X–ray (EDX) spectroscopy, and X–ray diffraction (XRD) analysis. The optimal work temperature of 300˚C was observed for the prepared samples. ZnO–GO–based sensor shows higher sensitivity than ZnO–rGO. Also, the variation of response and recovery time with the gas concentration is investigated. As is expected, the sensitivity increases as the gas concentration increases. Besides, it was revealed that the response and recovery time is a function of the surface morphology.