Solvothermal Synthesis And Properties Of One-dimensional Carbon-based Nanocomposites

In this dissertation, solvothermal route for the synthesis of one-dimensional (ID) nanostructures have been developed. By this way, the carbon nanotubes/nickel glycolate polymer (MWCNT/NGP) core-shell nanostructures, carbon nanotubes/magnetite microspheres (MWCNT/Fe3O4) heterostructures, and nickel glycolate polymer microtubes (NGPMs) were successfully prepared. Furthermore, the electrochemistry property, microwave absorbing ability, and the Cr2O2-absorbing ability in ultrapure water were investigated, respectively. The main contents of this paper were as following:1. A series of MWCNT/NGP core-shell nanostructures have been successfully synthesized in ethylene glycol medium using a solvothermal method, through which a conformal NGP layer was deposited onto the MWCNTs. Furthermore, the thickness of the NGP shell can be conveniently varied or controlled by the concentration of the metal salt (Ni(N03)2·6H2O). Cyclic voltammetry study has revealed that these hybrid nanostructures possess significantly enhanced electrocatalytic activity toward the oxidation of glucose for the first time. There is an optimum ratio of MWCNTs and Ni(NO3)2·6H2O of30:1(mg: mmol) at which the nanostructure obtained possesses the maximum electrocatalytic activity, wide linear range, and high sensitivity. These new MWCNT/NGP core-shell nanostructures have shown potential applications as nonenzymatic glucose sensors.2. Fe3O4microspheres were prepared via a facile solvothermal method using hydrous ferric chloride and anhydrous sodium acetate as materials, and ethylene glycol as solvent. Furthermore, the tunable denseness carbon nanotubes MWCNT/Fe3O4heterostructures were obtained by adjusting the ratio of ferric chloride and MWCNTs in the reaction system. In addition, microwave absorbing properties of FesO4microspheres and MWCNT/Fe3O4heterostructures were measured at a microwave frequency range of2-18GHz, and the results indicated that Fe3O4microspheres obviously possessed the ability of microwave absorption and the strongest absorbing peak shifted to lower frequency with the coating thickness increase. Compared to Fe3O4microspheres, MWCNT/Fe3O4heterostructures tend to absorb microwave at higher frequency and weaken absorption at lower frequency.3. According to the synthesis of MWCNT/NGP, NGPMs were further prepared via a facile solvothermal method using hydrous nickel nitrate and anhydrous sodium acetate as materials, and ethylene glycol as solvent. Furthermore, nickel oxide (NiO) microtubes were obtained by a high-temperature treatment in air atmosphere of NGPMs. As-prepared NGPMs are of hierarchical structure, which are composed of a lot of nanolamellas. The morphology of NiO microtubes directly derived from that of NGPMs. In addition, the experiments were conducted for adsorption of Cr2O12-in ultrapure water using the two kinds of microtube obtained as absorbers. The results reveal that NGPMs obviously possess a better ability of chromium absorption with a maximum absorbing value of14.6mg/g at pH of4than nickel oxide microtubes. Thus, the as-prepared of NGPMs may be promising as a new kind of adsorber for heavy metal ion for water treatment.