The Synthesis, Modification And Characterization Of Low-dimensional Nanostructured ZnO

Considering that pure ZnO only show the optical and electrical properties, we are devoted to the modification of nanostructured ZnO with another nanophase materials in order to impart new properties to it and to extend its applications in more fields. Three different modification strategies had been employed in this study, and Mn-doped ZnO nanorods, uniform ZnO nanorods coated with carbon, and ZnO/Fe3O4 hollow spheres were finally harvested.Colloidal undoped ZnO nanorods and Mn-doped ZnO nanorods were synthesized at low temperature via the decomposition of Zn and Mn precursors in the methanol solution of potassium hydroxide. The substitution of parts of lattice Zn of ZnO by Mn²⁺ ions is confirmed by XRD and XPS techniques. The nanorods are well crystalline and have a narrow size distribution. Their surfaces are surrounded by large amounts of hydroxyl groups, which results in their good solubility and dispersivity in water and alcohol. The doping of Mn²⁺ ions can tune the band gap and photoluminescent properties of ZnO nanorods.We have proposed a simple, microwave-assisted method for the accurate coating of carbon on the surface of ZnO NRs at low temperature. This method under-goes the process in a sequence consisting of the introduction of surface amino groups into ZnO NRs, the grafting of glucose, and microwave-assisted carbonization. With this method, the as-prepared carbon-coated product preserved the good dispersity and uniformity of initial ZnO NRs.Studies on the effects of carbon-coated ZnO nanorods and pure ZnO nanorods revealed that the coating of carbon remarkably reduced the cytotoxicity of ZnO nanorods. Carbon-coated ZnO NRs also exhibited excellent photocatalytic activity toward the decomposition of MB.ZnO/γ-Fe₂O₃ composites were synthesized by using Zn(acac)₂, Fe(acac)₃ as the raw materials, and PEG300 as the solvent as well as the medium of microwave heating. AOT and oleic acid were added as surfactant to form vesicles. These small nanoparticles grow into the nanocages with a self-organization method in vesicles. The morphology, structure and composition of the nanocages were characterized by means of the XRD, TEM, and FESEM. The effect of surfactant was investigated in detail.