3D ordered porous SnO_2 with a controllable pore diameter for enhanced formaldehyde sensing performance

摘要

This paper reports the preparation of 3D ordered porous SnO2 with different diameters (103, 546, and 1030nm) by a simple template method. We find that 103nm porous SnO2 nanomaterials have the highest response (30) and fastest response/recovery time (3/10 s) for 100 ppm HCHO (formaldehyde) compared with the response and response/recovery times for 546 nm (20 and 3/17s, respectively) and 1030 nm (10 and 6/20s, respectively) porous SnO2 nanomaterials at a low working temperature (220 degrees C). All three sensors show good long-term stability, repeatability, and linearity. The results show that decreasing the diameter of the porous SnO2 materials effectively increased the gas sensitivity to HCHO. The increase in the gas sensitivity was attributed to the ordered porous structures, large specific surface area, and additional oxygen vacancies on the surface.