Enhanced ethanol gas sensing properties of hierarchical porous SnO2-ZnO microspheres at low working temperature

In this work, the hierarchical porous SnO2-ZnO microspheres have been successfully synthesized by hydrothermal method followed by calcination. The structure, chemical composition, specific surface area and morphology of as-synthesized samples were detailed characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The results indicate that the response of hierarchical porous SnO2-ZnO microspheres-based sensor toward 100 ppm ethanol is 74 at low working temperature (225 degrees C), which is higher than that of pure hierarchical porous ZnO microspheres-based sensor (39). Moreover, the hierarchical porous SnO2-ZnO microspheres-based sensor presents fast response and recovery time (4 s, 6 s), good selectivity, repeatability and stability. Therefore, the sensor based on hierarchical porous SnO2-ZnO microspheres will be a potential candidate for ethanol detection.