Synthesis And Microstructures Of ZnO And ZnS One Dimensional Nanomaterials

ZnO and ZnS one dimensional nanomaterials were synthesized by thermal evaporation method. Morphologies and microstructures of as-synthesized products were characterized by X-ray diffraction, Scanning electron microscopy (SEM), high resolution transmission electron microscopy(HRTEM). Effect of growth parameters on nanostructures was clarified, growth mechanisms of several unique nanostructures were opened out. Properties of part as-synthesized nanostructures such as photoluminescence spectrum, wettability and field emission were measured.All kinds of ZnO and ZnS nanostructures were synthesized using vapor deposition method by adjusting experimental parameters such as pressure, temperature, substrate, source material types and proportion.Tower-like ZnO nanostructures have been synthesized successfully using ZnS and carbon powder as a source material in 900℃. the results showed Zn substrate play an important role, which promotes Zn microsphere precursors were oxidated into towerlike nanostructures. Fixing other experimental parameters, we alternated Zn foil as Si foil and tungsten fiol, no towerlike nanostructures can be grown.As-synthesized towerlike ZnO nanostructures are expected to have potential applications in protection of metal bulk Zn against corrosion in air as well as environmental friendly photo catalysis.Ringlike ZnO nanostructures have been synthesized through thermal evaporation of ZnS powder and using silicon foil coating Au film as a substrate. The results indicated that the ringlike structures were formed due to bend of (0001) polar surface dominated nanobelts induced by spontaneous polarization.ZnO/ZnS heterostructured rings were synthesized by thermal evaporation of ZnS and carbon powder.There is a novel phenomenon that lots of teeth are always at the inner surface of the ring. The bent nanobelts have an average thickness of 50 nm,width of 100 nm and length from several to several hundreds of micrometers. The nanobelts couldn't bend when the thickness is more than 100 nm.TEM results indicate the formation mechanism of the heterostructured nanoring is attributed to the strain induced bending that arises mainly from the lattice mismatch between ZnO and ZnS.ZnS saw teeth-like nanostructures have been synthesized without using any catalyst in 1020℃. Results showed that sawlike nanostructures are induced by the secondary growth along (0001) direction of wurtzite ZnS. The simple method can be applied to synthesize other nanostructures. We substitute Si substrate for ITO glass substrate, lots of fishbone-like ZnS nanostructures were synthesized successfully. Finally a rational growth mechanism was proposed.