| It is known that the size and shape of nano/micrometer materials have great influence on their properties and application. Thus, the synthesis of nano/micrometer materials with special morphologies and microstructures are of great importance for the basical and applied research of new functional materials. Ionic liquids with great advantage over the traditional solvents have been attractive for its abroad applications in the controlled synthesis of the inorganic nano/micrometer materials fields.In this work, Ionic liquids of [Bmim]C1, [Bmim]BF4 and [Bmim]HSO4 were prepared through substitution and metathesis reaction. The chemical structure and thermal stability of the final products were characterized by infrared spectra and thermal analysis. The Ni and Ag have been synthesized successfully in [Bmim]BF4 and [Bmim]C1 by solvothermal method and and reflux method through the decomposition of ionic liquid. The possible mechanisms for formations were proposed.β-Ni(OH)2 and TiO2 crystals with various morphologies were controlled synthesized in ionic liquids system. The obtained innovative results are as follows.(1) (3-Ni(OH)2 nanomaterials with different morphology, such as nanoflakes, nanoplatelet, regularly hexagonal nanoplatelets and nanorods, can be obtained in [Bmim]BF4 by solvothermal method. The effect of reaction conditions such as ionic liquids content, reaction temperature, reaction time and NaOH concentration were discussed. When the volume ratio of [Bmim]BF4 to water was 2:1, the products take on platelet-like shape and their thicknesses in the range of 10-15 nm. With the volume ratio of [Bmim]BF4 to water increasing to 1:1, The major morphology of sample is regularly hexagonal nanoplatelets with the thicknesses of 20-30 nm. With the volume ratio of [Bmim]BF4 to water further increasing to 1:2, the sample is composed of prismatic-like rods. Most nanorods have two even ends, while a few have a sharp tip and one even end or two tips. The diameters ofβ-Ni(OH)2 nanorods are in the range of 200-430 nm. The thicknesses of nanoplates were increased by increasing reaction temperature and prolonging reaction time. In addition,β-Ni(OH)2 nanoneedles and sub-microspheres have been successfully prepared in a room-temperature ionic liquid [Bmim][BF4] system by refluxing method. With decreasing the content of [Bmim]BF4 content, the morphologies ofβ-Ni(OH)2 was changed from nanoneedles to sub-microspheres.(2) The relationship between property and the morphology ofβ-Ni(OH)2 nanomaterials was studied. The results show that the as-preparedβ-Ni(OH)2 composite electrodes have better electrochemical performance, especially the nanoflakes.(3) Synthesis of mesoporous TiO2 particles using ionic liquid as template through sol-gel method was investigated and The mechanism for the formation of these nanostructured TiO2 particles is an effective aggregation of the TiO2 particles with a self-assembled ionic liquid. With increasing the contents of [Bmim]BF4, The BET surface area and pore volume of mesoporous TiO2 increased, but varying the content of water and ionic liquid have little effect on the BET surface area and pore volume of mesoporous TiO2. Furthermore, mesoporous TiO2 materials prepared with ionic liquid showed excellent photocatalytic activity and thermally stability. The photocatalytic activity of mesoporous TiO2 calcined at 500℃was higher than that of P25 and the anatase phase was present when the heat treatment temperature was up to 900℃.(4) Anatase nano/microstructures with various morphologies have been controlly prepared in ionic liquid [Bmim]BF4 by a refluxing method. Morphology evolution of anatase nanostructure from microspheres to integration of microspheres, again nanoparticles were realized with the varying amount of TiCl4, content of water, solvent, reaction temperature and reaction time et al. The photocatalytic activities of anatase nanostructures prepared were investigated. The results indicated that the photocatalytic activities anatase nanostructures increased with decreasing the crystal size.(5) TiO2 nanocrystals with hierarchical structures were prepared in ionic liquid medium under solvothermal condition. The conditions, mainly including concentration of ionic liquid, Ti source, reaction temperature, reaction time, types of ionic liquid and surfactant, were ranged widely to investigate the effect on morphologies and crystal phase of TiO2 materials. With decreasing the content of ionic liquid, the morphologies of anatase nanostructure can change from microspheres consisting of nanoparticles, to aggregate microspheres composing of nanoparticles, rectangular particles with layered structure, again sub-micron plates. And rectangular block consisting of nanorods and rectangular block with layered structure can obtained by increasing the reaction temperature and time. Pure anatase TiO2 was formed in [Bmim]HSO4 and [Bmim]BF4, whereas the crystal phase of TiO2 was pure rutile and the morphology was rod-like when the reaction carried out in [Bmim]Cl. A mechanism related with selective adsorption of imidazole salts on TiO2 crystal faces was proposed to explain the influence of imidazolize salts on morphologies and coordination theory of crystal was use to explain the formation of the rutile and anatase crystlas phase. Moreover, we study the relationship between property and the morphology of TiO2 nanomaterials. The effect of TiO2 morphology such as nano-scale, shape, arrangement style and crystal phase on Photocatalytic degradation of Rhodamine B was discussed. TiO2 microspheres consisting of nanoparticles and aggregate microspheres composing of nanoparticles or rectangular particles with layered structure had better photocatalytic activity.
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