The Preparation and Characterization of ZnO nanomaterials
Abstract: This article we discess the problem of Semiconductor nanocrystals exhibit outstanding properties totally different from those of the bulk materials due to the quantum size effect. The nanocrystals may find prospective application in many fields, such as high-speed optical calculation, optical switch,optical display and optical information storage.
In this dissertation,olvothermallhydrothermal methods have been developed father to prepare ZnO nanomaterials and a lot of characterizations have also been done. The detail is listed as following:
1 When the ZnO powders were synthesized by hydrothermal salt solution under high pressure, it can be found that it formed the shape like dendrite crystal, leaf crystal and sawtooth caystal. The formation of the orientation adhesion and dendrictic crystals of ZnO nanocrystallites was studied. The orientation adhesion of nanocrystallites and thedendritic crystals formed by connection of crystallites were discussed by the growthunit model of anionic coordination polyhedrons.
2 Without any other support during etching in dilute phosphoric acid aqueous solutions (18wt%)，alumina nano-tubes, nano-belts and nano-wires were fabricated from AAO under different etching times.Besides the etching effect of phosphoric acid on the structure, aloosening effect also occurs along the boundaries of the colloidbundles.Because of the incorporation of acid anions duringanodization, the composition of the individual cell wall is affected andthree different layers formed. Therefore, the etching rates of differentlayers of the cell wall are influenced, which leads to the formation of vamous nano-structures.
