| Considering the unique optical, mechanical, thermal and electrochemical properties for carbon nanotubes (CNTs), graphene (GS) and the excellent photoelectric conversion, magnetic,catalytic performance for the Ruthenium complexes, nickel nanoparticles (Ni NPs), palladium nanoparticles (Pd NPs), this thesis attempted to carry out the research of covalent and noncovalent functionalization of CNTs,GS and preparation a series of nanocomposites combination of the Ru complexes, Ni NPs, Pd NPs and the functionalization of CNTs and GS. We further investigated the application of the nanocomposites in photoelectric conversion, sewage treatment and catalysis.The main contributions are as follows:(1) A bi(2,2’-bipyridyl)-pyrene derivative ruthenium(Ⅱ) complexes anchored on graphene sheets (B-Ru-P/GS) nanohybrid was prepared utilizing a simple noncovalant method. The morphology, structure and spectroscopic properties of B-Ru-P/GS nanohybrid were systematic characterized by transmissionelectron microscopy (TEM), atomic force microscope (AFM),Raman spectra, and fluorescence spectroscopy. For the B-Ru-P/GS nanohybrid, the ECL signal at the electrode was obviously and steadily revealed. A reversible rise/decay of the photocurrent was observed and the photocurrent response of the B-Ru-P/GS nanohybrid was remarkably higher than that of the ruthenium(Ⅱ) complexes. Therefore, the B-Ru-P/GS nanohybrid is believed to have the potential use as for solid sensors, light emitting diodes and optoelectronic devices.(2) The magnetic Ni nanoparticles functionalized water-soluble graphene sheets nanocomposites (Ni@GSs-C(CH3)2COONa) were fabricated via a facile and mild strategy. The Ni NPs was immobilized on the surace of GS by high temperature gas reduction method. A simple and efficient covalent functionalized GS approach (the addition of cyano radicals) was used to improve the water solubility of nanocomposites. The morphology, structure, component, thermal stability and magnetic properties were verified by TEM, Raman spectra, X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and vibrating sample magnetometer. As a powerful tool, the Ni@GSs-C(CH3)2COONa nanocomposites had great potential as an effective absorbent for removing aromatic compounds from waste water and provided potential application in environmental issues owing to their rapid absorption rate,convenient magnetic separation and re-use property.(3) New catalysts consisting of perylene tetracarboxylic acid noncovalent functionalized GS support-enhanced electrocatalytic Pd nanoparticles (Pd/PTCA-GS) using different reducing agents including H2, NaBH4 and ethylene glycol were fabricated and used as anode catalysts in direct ethanol alkaline fuel cell (DEAFCs). The information of the morphologies, sizes,and dispersion of Pd NPs for the as-prepared catalysts was verified by TEM, Raman spectra and XRD. As the ethanol electro-oxidation anode catalysts, Pd/PTCA-GS exhibited higher electrocatalytic activity,better tolerance and better electrochemical stability than Pd/GS and Pd/C. Most attractively, the chemical reduction method remarkably affected the electrochemical behaviors. Among all the catalysts tested, Pd/PTCA-GS(NaBH4) exhibited the best kinetics, highest catalytic activity, best tolerance and best electrochemical stability than that of other as-prepared catalysts due to the dual role of the PDIL and reducing agent. What’s more, the strategy of PTCA functionalization is available to prepare other carbonaceous carrier supported metal nanoparticles for enhanced dispersivity, stability and catalytic performance, as well for being used in fuel-cell technologies.And the effects for chemical reduction methods could be used to design and develop more efficient catalysts.(4) A new catalyst consisting of ionic liquid (IL)-functionalized CNTs obtained through 1,3-dipolar cycloaddition support-enhanced electrocatalytic Pd nanoparticles (Pd@IL(Cl-)-CNTs)was successfully fabricated and used as anode catalysts in DEAFCs. The morphology, structure,component and stability of Pd@IL(Cl-)-CNTs were systematic characterized by TEM, Raman spectra, TGA and XRD. The Pd@IL(Cl-)-CNTs catalyst exhibited higher electrocatalytic activity,better tolerance and greater electrochemical stability than the Pd@CNTs, which was ascribed to the effects of the IL. Cyclic voltammograms at various scanrates illustrated that the oxidation behaviors of ethanol at all electrodes were controlled by diffusion processes. The investigation of the different counteranions demonstrated that the performance of the IL(X-)-CNTs hybrid material was profoundly influenced by the subtly varied structures of the IL moiety. All the results indicated that Pd@IL(Cl-)-CNTs is an efficient anode catalyst, which has potential applications in DEAFCs and the strategy of IL functionalization of CNTs could be available to prepare other carbonaceous carrier supports to enhance the dispersivity, stability and catalytic performance of metal nanoparticles as well.(5) A new catalyst consisting of IL derivative from perylene tetracarboxylic acid functionalized nitrogen-doped GS support-Pd nanoparticles (Pd/PDIL-NGS) was prepared and used as anode catalysts in DEAFCs. The PDIL-NGS was synthesized through a mild hydrothermal route with PDIL as functional molecules, graphene oxide as raw material and urea as nitrogen sources. The nitrogen doped into the graphene lattice and the efficiently functionalized of NGS by PDIL were verified by Raman, XRD, XPS and UV-Vis absorption spectra. The results from systematic analytical techniques suggested the N-doped and introducing PDIL molecules not only improve the machining capacity but also improve the ability to transfer electrons for the support material. The Pd/PDIL-NGS possessed larger electrochemically active surface area and greater processing performance and exhibited better kinetics, higher electrocatalytic activity, better tolerance and better electrochemical stability than Pd/C and Pd/NGS, which illustrated that the new catalyst had potential applications in DEAFCs. |
PDF Full Text Request