One-pot synthesis of 3D hierarchical SnO2 nanostructures and their application for gas sensor

3D hierarchical SnO2 nanostructures, constructed by well-defined 1D SnO2 nanorod units, were synthesized by a facile, one-step hydrothermal route, only using simple inorganic compounds SnCl4·5H2O and NaOH as starting materials, without using any surfactants and templates. The prepared 3D SnO2 hierarchical nanostructures were applied to fabricate a gas sensor for selectively detecting n-butanol. The gas sensing results demonstrated that the 3D SnO2 hierarchical nanostructure sensor exhibited excellent gas sensing performances to ppm-level n-butanol in terms of high response, good reproducibility, fast response–recovery characteristics and superior selectivity, and significantly enhanced response compared with the commercial SnO2 nanopowder sensor. The enhanced gas sensing performances could be attributed to the facilitated molecular absorption, gas diffusion and mass transport induced by the unique 3D loose and porous structure, and the high surface-to-volume ratio resulted from the 1D rod-like nanostructure which could provide more active sites for gas absorption. It was believed that the 3D hierarchical SnO2 nanostructures could also further offer a potential opportunity for other applications such as lithium-ion batteries, catalysis and dye-sensitized solar cells.