Synthesis and characterization of hierarchical porous SnO2 for enhancing ethanol sensing properties

Hierarchical porous SnO2 (HP-SnO2) nanoparticles (NPs) were synthesized via a modified sol-gel method by employing polystyrene (PS) microspheres as a template and SnCl2 as a tin source. The samples presented a three-dimensional random arrangement of macropores with average pore diameter of about 210 nm, of which the pores walls were composed of NPs with the size of about 11 nm. The N-2-sorption analysis showed that the presence of the hierarchical mesoporous structure in the samples. The gas sensing measurements showed that the response of HP-SnO2 based sensor reached the maximum value at the operating temperature of 240 degrees C, which was 60 degrees C lower than that of SnO2 based sensor. Moreover, the HP-SnO2 exhibited a significant improvement for the response and a short response-recovery time to ethanol vapor. The results indicated that HP-SnO2 NPs were of great potential for application in ethanol sensors. (C) 2015 Elsevier B.V. All rights reserved.