Research Article

Catalyst-Free Synthesis of Hollow-Sphere-Like ZnO and Its Photoluminescence Property

Figure 5

Schematic illustration of the proposed growth mechanism for the formation of hollow-sphere-like ZnO. The upper section is the SEM diagrams of the product prepared at different reaction stages ((a) the second stage; (b) the third stage; (c) the fourth stage), and the lower section is the schematic diagram of the change of product’ s structure during the reaction process: (I) formation of Zn clusters; (II) surfaces of Zn clusters oxidized into nanocrystallite islands; (III) micro- or nano-Zn liquid in the core of Zn clusters evaporated to supply unsaturated Zn vapors from the nanopores; and (IV) formation of ZnO hollow sphere with nanopores or holes.
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