Liquid Phase Synthesis And Morphology-control Of Inorganic Micro/Nanomaterials

In our dissertation, morphologies-controllable synthesis by organic compounds saaisted solution-based chemical routes were developed to prepared inoraganic function nanomaterials. Based on a wide and in-depth literature investigation, combined with the equipments and other condition of our laboratory, the facile hydrothermal and solventthermal system were selected as the research field. different experimental routes and reaction conditions in hydrothermal method were investigated, by which a series of functional materials with nanostructures and sub-nilcron structures were synthesized, such as rare earth oxides (CeO2), the semiconductor light-emitting materials (ZnO) and carbonate (SrCO3) were successfully prepared.In this thesis, The shapes, crystal structure and effective conditions of the as-obtained products have been studied. In addition, The influence of the experimental parameters on the morphologies of as-prepared samples and the corresponding growth process have also been investigated. The research results we acquired were as follows:1. Rodlike, square-like, truncated octahedral and hexagonal shape of well-dispersed CeO2nanocrystals in a cubic fluorite structure have been achieved controllably via an ethylenediamine-assisted hydrothermal process at different temperatures and time. In the case of using polyvinyl alcohol (PVA) as a stabilizer, ethylene diamine acts as OH-provider and the capping reagent, respectively. The optical properties and the band gap energies of different morphological samples were aslo performed by ultraviolet visible (UV-Vis) spectroscopy which exhibited a strong absorption and a light blue shift around200-400nm. Moreover, the rational evolution mechanism is proposed for the formation of different shapes.2. ZnO fan-like nanomaterials were synthesised by hydrothermal synthesis route, using egg albumin as a nanoreactor, PVP as a stabilizer and the selective adsorption of PVP on different crystal faces, N2H4·H2O as the solvent. The samples were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), ultraviolet visual (UV-Vis) spectroscopy. The photocatalytic activity of ZnO nanocrystal was by investigated by degradation of methyl orange. Furthermore, the formation mechanism of fan-like ZnO nanomaterials was discussed in detail by the obtained products. Results showed that the method is a facile, effective way to synthesis ZnO fan-like nanomaterials. The photocatalytic activity of ZnO fan-like sample remaerkably increased。3. In this paper, diverse structures and morphologies of SrCO3nanomaterials have been obtained via a facile solventthermal process in a mixed solvent of ethylenediamine (EDA), ethonal, PEG-200. In the case of using PVP as a "soft" tenplate,(NH2)2CO and Sr(NO3)2as the raw materials source. The samples were characterized by X-ray diffraction (XRD), SEM, Fourier transform infrared (FT-IR). It was found that the strong chelation of the solvent EDA and PEG-200, the content of PVP, as well as the ratios of the solvent components were the great importance for the formation of the final structures. The rational evolution mechanism would be discussed.