Synthesis And Properties Of Cobalt, Vanadium Compound Nanomaterials

Cobalt and vanadium compound nanomaterials show unique structure and special properties, which can be widely used in electrochemistry, magnetic recording materials, optics, catalysts, cell, sense and other fields, and become an important topic in the fields of chemistry, material sciences and physics. In this dissertation, cobalt, vanadium compound nanomaterials with different crystalline structures, composition and morphologies have been synthesized by hydrothermal synthesis process and their properties have been investigated.The main research contents of this dissertation are as follows:Firstly, we chose Co(NO3)26H2O, Na2SeO3as precursors, and N2H4H2O as a reducing agent. Co(0.85)Se with various shapes was synthesized under in the different hydrothermal conditions, including ratio between reactants, reaction temperature and reaction time. The tremelliform Co(0.85)Se nanosheets were obtained via one-step hydrothermal synthesis method in the typical synthesis condition. The tremelliform Coo.85Se nonosheets have a high specific surface area. And magnetism test results show that the tremelliform Co(0.85)Se possesses paramagnetic property at room temperature. Experiments have shown that the Co(0.85)Se nanosheets synthesized under the optimal reaction condition have excellent catalytic activity and reusability in the process of decomposition of N2H4· H2O. The Co(0.85)Se nonosheets were applied to catalyze decomposition of N2H4· H2O as catalyst. This was especially significant in widening the application ranges of cobalt selenide nanomaterials.Secondly, on the basis of previous studies, the tremelliform Co(0.85)Se nonosheets is applied to the adsorption-desorption equilibrium of methylene blue trihydrate in the presence of sodium borohydride. The results display that the Co(0.85)Se nonosheets have efficient catalysis for the decomposition of sodium borohydride. The adsorption capability of the Co(0.85)Se nonosheets for methylene blue trihydrate has been improved obviously due to the decomposition of sodium borohydride. And, after arriving at absorption and desorption balance time, the absorbed methylene blue trihydrate could be released from the surface of Co(0.85)Se nonosheets while sodium borohydride decreased. Thus, the dye and adsorbent can be easily reused and recycled. Zeta potential and the pH of the nanosheets in the equilibrium process has been tested to infer the adsorption mechanism. We explained the function of sodium borohydride by adjusting its amountThirdly, based on the structural characteristics of both vanadium pentoxide and ionic liquid structure, organic-inorganic hybrid V2O5/bmimBr nanobelts with thicknesses of30-50nm and width of200-300nm have been synthesized via a hydrothermal reaction. The composition and structure of the V2O5/bmimBr nanocomposites have been characterized by elemental analysis and inductively coupled plasma (ICP), X-ray photo-electron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). And the function of ionic liquid in the formation of V2Os/bmimBr has been investigated via adjusting the dosage of ionic liquid in the hydrothermal reaction system. Experiments have shown that the conductivity of the products has got very great improvement after inserting the ionic liquid into the vanadium pentoxide.