Polyvinylpyrrolidone-assisted ultrasonic synthesis of SnO nanosheets and their use as conformal templates for tin dioxide nanostructures.

Single crystalline SnO nanosheets with exposed {001} facets have been prepared by an ultrasonic aqueous synthesis in the presence of polyvinylpyrrolidone, which hinders the spontaneous formation of the truncated bipyramidal SnO microcrystals and exfoliate them into layer-by-layer hierarchical structures and further into separate SnO nanosheets. The SnO nanosheets have been used as conformal sacrificial templates converted into polycrystalline SnO(2), as well as layered SnO/SnO(2) nanostructures, by calcination in air. The concept of fabrication of two-dimensional tin oxide nanostructures demonstrated here may be relevant for the crystal design of layered materials, in general.