Fabrication of hierarchical zinc oxide nanostructures through multistage gas-phase reaction

摘要

A hierarchical nanostructure of wurtzite zinc oxide (ZnO) was synthesized by the thermal evaporation of Zn/ZnO powders. It had a hexagonal prism as the center and six clusters of nanorods as the branches. The formation of this ZnO nanostructure is attributed to three sequential catalyst-free reactions. First, a Zn prism was deposited on the substrate as the result of the condensation of Zn vapor; then, oxygen was introduced in an appropriate temperature range and the Zn prism was oxidized; finally, secondary ZnO nanorods grew on the ZnO surfaces of the central prism and the snow flake-shaped nanostructure was attained. This work has revealed the perspective of achieving hierarchical ZnO nanostructures through simple and controllable gas-phase reactions.