Hydrothermal synthesis of flake-flower NiO architectures: Structure, growth and gas-sensing properties.

Nanomaterials with hierarchical architectures consisting of two-dimensional nanostructures have attracted considerable attention for their potential applications in recent years. In current work, flake-flower NiO architectures self-assembled by aggregative nanosheets have been successfully synthesized via the hydrothermal route. It is notable that the NiO sensors exhibit excellent gas sensing performances owing to the open and well-defined structure as well as abundant micro reaction rooms built by two-dimensional ultrathin nanosheets, which are thinner than the thickness of electron depletion layer. Moreover, a possible growth mechanism for the interactions between PVP and Ni 2+ ions in the synthesis of the precursors Ni(OH) 2 and the novel morphology evolution of the NiO nanoflowers are proposed in detail. [ABSTRACT FROM AUTHOR]