3D ordered porous SnO2 with a controllable pore diameter for enhanced formaldehyde sensing performance

Abstract

This paper reports the preparation of 3D ordered porous SnO2 with different diameters (103, 546, and 1030[Formula: see text]nm) by a simple template method. We find that 103[Formula: see text]nm 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 3/17[Formula: see text]s, respectively) and 1030 nm (10 and 6/20[Formula: see text]s, respectively) porous SnO2 nanomaterials at a low working temperature (220∘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.