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

Abstract

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 °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.

GRAPHICAL ABSTRACT

Keywords:

• Hydrothermal method
• ethanol
• gas sensor
• heterojunction

Acknowledgements

The authors are very grateful to Prof. Li Liu for sufficient help in explanation of chemical transformations and interpretation of results of the XRD analysis of structures.

Competing interests

The authors declare that they have no competing interests.