Low-Dimensional Oxide Nanostructures: Wet Chemistry Synthesis,Characterization And Properties

Oxide is one type of inorganic compound widely spreading in the nature. Due toits unique chemical and physical properties and broad applications in many fields,oxide is of great importance to the proceedings of industry and agriculture andresearches of science. A history mission in the current chemistry and materialsscience is how to find and produce functional oxide materials with new structures,and how to precisely control the crystal structures, sizes, morphologies anddimensionalities, further to achieve the tailoring of physical/chemical properties ofthe materials. Wet chemistry method proved to be a great way to reach the goal. Inthis dissertation, low-dimensional nanostructures of binary and ternary oxides aresuccessfully synthesized via wet chemistry by modulating the parameters such assolvent, pH, precursor and additive.Polymorphous zirconia (ZrO2) is synthesized via wet chemistry method:Polymer-stabilized metastable tetragonal (t-ZrO2) nanopowders have been preparedby microwave-assisted heating in an aqueous solution containing PVA;hydratedzirconia (ZrO2·H2O) nanopowders have been synthesized via sonochemical method;monodispersed monoclinic zirconia (m-ZrO2) nanoparticles have been produced viahydrothermal method in ethanol-water system. Nickel oxide (NiO) nanorings havebeen synthesized by the phase transition from hexagonal Ni(OH)2 to cubic NiO viahydrothermal-annealed method.A facile general synthesis route to a family of chromate one-dimensionalnanostructures has been established. The effects of pH and surfactant on phase andmorphology formation in the crystal growth have been systematically investigated.The physical properties, such as dielectric, electrochemical, UV-Vis absorbance, andphotoluminescent properties, of the as-synthesized chromate nanocrystals have alsobeen studied.One-dimensional nanostructures of metal borate are successfully synthesized viasolution-phase method at low temperature, approximately 700℃~900℃ less thanthat in conventional solid-state reaction. Eu2+ and Eu3+ doped borate fluorophors havebeen selectively synthesized in the ethanol-acetone solvent and water solvent,respectively. The fluorophor, exposed to UV, emits blue-violet and pink lightrespectively. The thermal stability and PL properties have also been investigated.