Hydrothermal synthesis of novel SnO2 nanoflowers and their gas-sensing properties

Self-assembly of one-dimensional nanoscale building blocks into functional 2D or 3D complex superstructures has stimulated a great deal of interest. In current work, using the hydrothermal method and reagent of hexamethylenetetramine (HMT), we synthesize the SnO2 3D hierarchical nanostructures with an average diameter of 200-400 nm, which exhibit flower-like architectures assembled by numerous one-dimensional tetragonal prism nanorods. Further comparative studies demonstrate that the HMT provides nucleation sites for the assembling of the nanorods, which plays a crucial role in producing such unique flower-like architectures. Meantime, a novel growth mechanism is proposed in detail. In property, the prepared SnO2 nanoflowers show excellent gas-sensing performances to ethanol of 50 ppm at an optimal temperature as low as 250 degrees C. Such unique architectures may open up an avenue to further enhance the gas-sensing performances of SnO2 nanostructures for future sensor application. (c) 2013 Elsevier B.V. All rights reserved.