Unique hierarchical Sn3O4 nanoflowers decorated with ZnO nanoparticles and their formaldehyde gas sensing properties

Abstract

Gas sensors with high response are highly desirable for the detection of harmful gases in real-time. Herein, the ZnO nanoparticles decorated hierarchical Sn3O4 nanoflowers are synthesized by a hydrothermal method. The gas sensor based on the ZnO/Sn3O4 composites exhibits excellent sensing properties to formaldehyde with a low operating temperature of 180°C. Specifically, the sensor has a response value of 44 for 100 ppm formaldehyde and a fast response time of 5 s. Moreover, it is noteworthy that the proposed gas sensor shows a wide detection range and a low detection limit of 1 ppm. Besides, the ZnO/Sn3O4 sensor exhibits good selectivity for formaldehyde and perfect reproducibility. The sensing mechanism of the gas sensor is discussed, and the heterojunction between ZnO and Sn3O4 enhances the sensing performance of the proposed gas sensor.