Controlled Fabrication And Property Studies Of Functional Micro/Nano Materials

Nano-materials have many special physical and chemical properties obviously different from their bulk counterparts or single molecules, due to the unique volume effect, quantum size effect, and macroscopic tunnel effect. For example, nanomaterials show both high activity and good selectivity in chemical reaction; compared with the bulk materials, nano-materials display blue-shiprt in their absorption spetra; semiconductor nanoparticles have their large absorption section. The unique properties of nanomaterial endow them wide potential applications in many fields such as electronics, chemistry, chemical engineering, life science and so on. However, the property of nanomaterials are greatly depend on their size, shape and structure, therefore, the controlled synthesis and the study of the relationship between the structure and property of nanomaterials are of great importance for both fundamental research and practical application. The main contents of this thesis are summaried as follows:1. Synthesis and property studies of copper-based nanomaterials1) Synthesis and property studies of porous copper/carbon and copper oxide nanostructures. Copper-based nanomaterials have various of physical and chemical poperties. Porous structure would endow the nanomaterials with large surface area, which may lead to some special physical chemical functions. We proposed a facile method for porous copper/carbon and copper oxide nanostructures. By using coordination between Cu2+and glycine (Gly), the precursors of Cu-Gly nanorods or nanosheets were synthesized at room temperature. The one or two dimensional nanostructure of porous Cu/C or CuO were obtained by calcining the precursors in different gas atmospheres. The studies of the antibacterial properties and decolorization of methyl orange (MO) revealed that the obtained materials exhibit significant antibacterial properties and photocatalytic fuction.2) Synthesis and property studies of Cu2O micro/nano structures. Because the physical and chemical activities of nanomaterials are associated with the surface morphology, the systematical tuning the structure, size and morphology of the inorganic nanomaterials has become a hot topic in the current materials research. In this section, we proposed a glycine-assisted double-solvent thermal approach to controllably synthesize a series of CU2O microcrystals. In water-ethanol system, the products have predominantly octahedral and polyhedral structures; while in water-glycol system or awater-glycerin system, the products have more tendencies to form a cubic type structure. Compared with the conventional route, this method provides a mild technique for various morphologies of Cu2O and omits the need for template or surfactants. The investigations of the antibacterial activity of the obtained Cu2O crystals suggest the obtained Cu2O crystals have good antibacterial effects, which transits from universality to selectivity with the transition of the crystal structure from cubic to octahedron. The study of these crystals for photodegradation of rhodamine B indicate that all these products have great catalytic activities, which are also influenced by the mophorlogies.3) Synthesis and property studies of copper micro/nano structure. Fabrication of nanostructure and the ordered functional structure assembled by nanoparticle will provide great oppertunity to explore their new functions. We used glucose, one of the biomolecules, to assist the synthesis of brand new puzzle-like copper microstructures and applied them as nonenzymatic glucose sensors. Compared to the commercial copper powders, the glucose-produced Cu micropuzzles show good linear dependence and high sensitivity and selectivity to glucose concentration change as nonenzymatic glucose sensors. Moreover, antibacterial tests show that the Cu micropuzzles have good antimicrobial efficiency, which would make the Cu glucose sensor applicable in the actual glucose detections. 2. Synthesis and propertiy studies of nickel-based materials1) Synthesis and property studies of NiO nanotubes. Due to low density, high pore rate and large surface/volumn ratio, hollow inorganic nanomaterials have shown important properties and potential applications. In this chapter, we developed a simple and convenient precursor approach for the synthesis of NiO nanotubes. By using coordination between Ni and dimethylglyoximato, one-dimensional metal complex bis(dimethylglyoximato) nickel(Ⅱ), Ni(dmg)2was synthesized and then used as precursor to produce NiO nanotube by calcining in the air. The obtained NiO nanotubes show good antibacterial properties compared to commercial NiO and synthetic NiO nanoflowers. Also, the NiO nanotubes exhibit effective electrochemical capacitance, which can be used as a supply of energy in the exothermic system. The magnetic measurement demonstrates that unlike antimagnetic bulk NiO, the NiO nanotubes are magnetic and may be used in fields of MR imaging and magnetic drug delivery.2) Synthesis and property studies of NiO nanowires. Nanowires, as a kind of one-dimensional nanostructure, are perfect nanomaterials for the functional device, and are also the symbol of the smallest size for the effective electron transfer. Conductivity is one of the important aspects of the electrode materials, which can enhance the efficiency of the active materials and reduce the inner resistance. In this study, we proposed an easy synthesis route of NiO nanowires with different lengths by calcining Ni foil after soaking in LiOH solutions. The length of NiO nanowires can be adjusted by the varying the concentration of the LiOH solution. The electrochemical capacitor property measurements of these NiO nanowires/Ni foil electrodes show that the length of the NiO nanowires has an obvious effect on their electrochemical properties. The NiO nanowires/Ni foil electrode with the longest length has a highest specific capacitance of180.00F g-1and long-term electrochemical stability3) Synthesis and property studies of nickel orthoborate nanoribbons. Metal borates possess important properties and great application potentials in many fields, such as non-linear optics, laser application, magnetism, catalytic and phosphorescent properties. We firstly synthesized nickel orthoborate Ni3(BO3)2nanoribbons via a facile solid state reaction. The obtained Ni3(BO3)2nanoribbons have widths between100-150nm and lengths up to20μm. The antimicrobial studies show that the Ni3(BO3)2nanoribbons have good antimicrobial activities towards gram-negative bacterial and gram-positive bacterial. In addition, we also explored the application of the Ni3(BO3)2nanoribbons in electrochemical capacitors and found that the Ni3(BO3)2nanoribbons have a large specific capacitance of170F·g-1.4) Synthesis and properties studies of TiO2-nickel magnetic photocatalysts. In practical industry, separation procedures of the catalysts, such as centrifugation or filtration, may result in the loss of the catalysts or the waste of much energy. Recently, using magnetic nanoparticles for separation of catalysts have been received great attention. In this study, we demonstrated that by using the magnetic force lines as invisible templates nickel one-dimensional (1D) urchin-like structure can be successfully obtained. The1D urchin-like Ni nanostructures cross each other and result in many gaps or spaces to make them easily be modified by TiO2. The photocatalytic and biocompatibility studies show that this TiO2/Ni composite remains the outstanding photocatalytic activity for organic pollutant decomposition and the biocompatibility of TiO2. But more importantly, because of the coexistence of magnetic Ni nanostructure, the composite also displays good magnetic properties, which enable the photocatalysts to be easily separated and recycle-used.3. Synthesis and properties studies of Mn-based nanomaterials1) Synthesis and properties studies of Mn3O4nanotube arrays and nanowire arrays. Mn-based materials are very important and well-investigated, and have been widely used in magnetical materials, catalytic, ion exchange as well as batteries. In the electronic industry, Mn3O4can be widely employed as soft magnetic materials. Orded micro/nano structures especially the ordered structures of the one-dimensional nanostructure might have very special magnetic properties,. In the section, we reported a mild route to synthesis of self-supported pattern of aligned Mn3O4nanotubes and nanowires under mild hydrothermal conditions without any substrates used. Mn3O4nanotubes/nanowires can grow into perfect aligned arrays on Mn3O4plates. The magnetic studies show that Mn3O4nanotube arrays have a larger magnetic capacity than Mn3O4nanowire arrays2) Synthesis and properties studies of β-MnO2network structures. β-MnO2is very easy to be prepared due to its stability in thermodynamics. Conventional β-MnO2usually exhibits very low electrochemical activities. In this study, we have successfully synthesized a long-range order two dimensional (2D) β-MnO2network structures assembled by β-MnO2nanowires by a mild solution method without the assistance of templates/substrates. Moreover, the2Dβ-MnO2network structures show good electrochemical performances with a capacity of381.2F/g at room temperature, which would offer great potential in next generational electrochemical supercapacitor.4. Synthesis and properties studies of other nanomaterials.1) Synthesis and properties studies of hyperbranched ferric phosphate nanostructures. In this work, we reported a simple, mild route to synthesize hyperbranched ferric phosphate nanostructures. The obtained hyperbranched ferric phosphate nanostructures show highly selective capture ability for phosphopeptides. The toxicity test of these materials shown they have good biocompatibility, and the low toxicity level would lead them to have promising application in the field of life sciences.2) Synthesis and properties studies of fusiform zirconia-GO hybrid composites (FZGO) nanostructures. During the last two decateds, nanostructured zirconium oxides have been widely used in the capture of phosphopeptides. In this section, we have successfully used GO to act as a nanostructure-directing template to synthesize zirconia fusiform nanostructures on GO. More importantly, the obtained FZGO show highly selective capture of phosphopeptides. The FZGO would be a kind of promising nanomaterials might to applied as the affinity probes for the specific capture of phosphopeptides from complex tryptic digests with the detection of MALDITOF mass spectrometry.