Fast formaldehyde gas sensing response properties of ultrathin SnO2 nanosheets

Ultrathin SnO2 nanosheets have been successfully synthesized through a simple low temperature hydrothermal strategy and developed for formaldehyde gas detection. Morphology characterizations are confirmed by the results of FESEM, TEM and HRTEM. The ultrathin SnO2 nanosheets are configured as high performance sensors to detect formaldehyde, and show very fast response times (<1 s), recovery times (6 s), good repeatability and selectivity at a relatively low working temperature. The high sensitivity performances are attributed to the morphology characterizations of ultrathin SnO2 nanosheets for affording large specific surface areas and more direct conduction pathways. The growth mechanism of the ultrathin SnO2 nanosheets and a morphology dependent sensing mechanism are proposed.