Constructing 3D porous SnO2 nanomaterials for enhanced formaldehyde sensing performances

Abstract

3D porous SnO2 nanomaterials enhanced gas sensitivity properties for formaldehyde has been successfully prepared by a simple template method. The morphology of the synthesized SnO2 was observed by a scanning electron microscope (SEM) as a 3D porous structure with a pore diameter of 120 nm. We systematically studied the gas sensing performance of 3D porous SnO2 and particulate SnO2. The result shows that the response value of 3D porous SnO2 to 100 ppm formaldehyde gas was 51.0 at low temperature 230 ℃, which was 6.4 times higher than that of particulate SnO2 (8.0), and the response/the recovery time of 3D porous SnO2 was 8 s/15 s. The minimum detection concentration of 3D porous SnO2 was 0.5 ppm formaldehyde with the response value of 2. However, particulate SnO2 can only be detected 10 ppm with the response value of 2. In addition, the selectivity coefficient of 3D porous SnO2 for formaldehyde was up to 7, which is better than particulate SnO2 (1). The reason for the enhanced sensitivity of 3D porous SnO2 formaldehyde gas is not only related to its porous structure and smaller grain size, but also to the increase in oxygen vacancies.