| Transition metal oxides such as zinc oxide, and copper oxide are versatile functional materials. For example, zinc oxide has received extensive applications in electronics, chemical engineering, medicine etc., and copper oxide has been widely used in catalysis, electronics, superconductors, medicine and so on. In this work, we have made systematical research on the hydrothermal synthesis, formation mechanism and optical properties of ZnO microcrystals in the presence of copper ion by virtue of comparability in ion radius with zinc ion and copper ion. Meanwhile, CuO microcrystals also have been prepared with the coexistence of zinc ion.In this thesis, effect of sonication assistance and copper ion on the morphologies of ZnO microcrystals were investigated, and the results show that uniform protruding-hexagonal-prismlike ZnO microcrystals were obtained with the synergetic effect of sonication assistance and copper ion coexistence. Furthermore, ZnO with this morphology has excellent luminescence property.In combination with the corresponding theory concerning nucleation and growth of ZnO crystals, we have also analyzed the components, structures and morphologies of the products synthesized under different hydrothermal times and the variation of ion constitute in the solution, and herein we believed that ZnO has experienced preparation of precursors, formation of crystal nucleus and growth, Ostwald ripening and growth termination stage, which in the end have displayed protruding-hexagonal-prismlike and dumb-belllike structure in the presence of copper ion and sonication assitance. Meanwhile, we have realized controllable synthesis of ZnO by altering concentration of copper ion, pH values of the precursors and the hydrothermal temperature.Meanwhile, tamato-like CuO microcrystals were fabricated with zinc ion in existence, and we speculate that crystallization of this morphology should be due to oriented aggragation of CuO nanowires.
|
PDF Full Text Request