Solution-Based Synthesis, Characterization And Property Investigation Of Low-Dimensional Functional Nanomaterials

Manipulated synthesis of nanoparticles is one of the most importantsections of nanoscience and nanotechnology, and also the base to investigatethe distinctive properties and applications of nanostructures. This thesisstudied solution-based manipulated synthesis of low-dimensional functionalnanostructures, emphasizing on the relationship between crystal symmetryand shape/properties manipulation of nanoparticles, and new method tocore/shell structured functional nanoparticles.In the aspect of investigating dimension and shape manipulated synthesisof low-dimensional functional nanomaterials, results on selective synthesis oftitanate nanotubes, nanosheets and nanobelts evidenced the relationshipbetween layered structures and single crystal nanotubes, clarified the confusedcognizance on structural characterization and formation mechanism on "TiO2nanotubes". The relationship between nanocrystals growth behavior andcrystal symmetry was also revealed through manipulated synthesis of CaF2,ZnO, and GaOOH nanocrystals in varied crystal symmetry.Oxide@C core/shell nanostructures constructed with kinds of oxides ascores and carbonaceous poly-saccharide-like polymer as shells were preparedin one pot by making use of the coupled hydrolyzation of metal chloride saltsand carbonization of glucose under hydrothermal condition. This method wasexpended to "post-synthesis" encapsulation of oxide nanoparticles such asFe3O4. Their conversion to hollow and composite structure was also realized.Carbonization of glucose taking place without any precursors formed ledto formation of monodispersed carbonaceous polysaccharide microspheres.Using as precursor, it constructed core/shell structures with noble metalnanoparticles. Using as template, a novel general method to prepare oxidesand nitrides was developed. Some distinctive optical and gas-sensingcharacteristics were found on the hollow spheres.Coupling the reduction of noble metal salts and carbonization of glucose,core/shell nanostructures composed of noble metal nanoparticle cores andcarbonaceous poly-saccharide-like shells were manipulatively synthesized.Under the mediation of PVP (poly (vinyl-pyrrolidone)) molecules, Ag@Cnanostructures with carbonaceous shells and Ag cores in the form ofnanoparticles and one-dimensional nanowires with different cross-sectionsymmetry were manipulatively synthesized. Distinctive surface plasmaresonance was observed on the Ag cylindrical nanowires, which evidenced thetheoretical prediction. An amorphous layer coating induced growth model tocylindrical nanostructures was proposed. The carbonaceouspoly-saccharide-like shell formed through carbonization of glucose, has richfunctional groups and consequent biocompatibility, which opens a new avenuefor application of inorganic functional nanomaterials in bionanotechnology.