4.3.4 Synthesis and gas sensing properties of hierarchical SnO2 nanostructures

Abstract

We have successfully prepared hierarchical SnO 2 nanostructures via a facile hydrothermal synthesis method.Field emission scanning electron microscopic and transmission electron microscopic results reveal that these hierarchical nanostructures are built from two-dimensional (2 D) nanosheets with edge thicknesses of about 8 nm.Gas sensing tests show that the sensor using hierarchical SnO 2 nanosheets exhibits high response and good selectivity to ethanol.Moreover, the sensor shows superior gas sensing performance compared with the sensor based on conventionally prepared SnO 2 nanoparticles.For example, at an ethanol concentration of 100 ppm, the response of the SnO 2 nanosheets is about 32.7, while the response is about 11 for nanoparticles.The enhancement in gas sensing properties is attributed to their unique structures.