Construction and Application of Metal-based Micro/Nano-sized Materials

Author:Ge Dan Hua

Supervisor:gu hong wei

Database:Doctor

Degree Year:2017

Download:59

Pages:156

Size:11833K

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Nanomaterials,because of their unique sizes and structures,have the special nature including the surface effect and volume effect,small size effect,macroscopic quantum tunnel effect and so on.Moreover,they can exist in various forms such as nanowires,nanorods,nanospheres,nanoparticles and nanofibers,etc.Transition metal oxide nanomaterials mainly consist of transition metal elements and oxygen,which at the same time have the general characteristics of nanomaterials and possess extensive applications in many fields.In addition,metal-organic frameworks materials(MOFs)are constructed by coordination assembly of metal ions or metal clusters and the organic ligands with large surface area,porous properties,abundant carbon skeleton,controllable structure and function and therefore are widely used in various fields.In pace with the rapid development of the global economy,it also inevitably brings the energy crisis and environmental problems,thus the development of high-performance power sources and green catalysts has been a research hotspot.Compared with the conventional secondary batteries,lithium-ion batteries(LIBs)have more advantages:environmentally friendly,recycled,light quality,high specific energy density and so on.As we all know,nano-sized electrode materials have larger specific surface area,bigger electrical conductivity and shorter ion transport diffusion path.On the other hand,selective catalytic reaction plays a very important role in the current chemical industry,which is the key to build green sustainable chemical processes.In this paper,the main research is about the synthesis of micro/nano-metal materials as well as the research of their lithium storage properties and catalytic activity.Through the development and design of novel nanomaterials,the screening of pyrolysis conditions and catalytic reaction factors,our nanomaterials exhibit excellent electrochemical performance in LIBs and high catalytic activity in catalytic oxidation.So it may be beneficial to promote the development of the next generation of LIBs and can broaden the application in catalytic industry.The work includes the synthesis of transition metal oxide,MOF materials and noble nanomaterials as well as their electrochemical properties and catalytic performance.The main contents are as follows:(1)Synthesis of nanomaterials:transition metal oxide nanomaterials,metal-organic frameworks materials and noble nanomaterials.And the morphology,composition,surface atomic distribution,valence state and stability of the as-prepared material were characterized by the scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),thermogravimetric analysis(TGA),and so on.(2)Study on electrochemical properties:Firstly,the porous Co3O4 nanospheres were prepared by the coordination assembly of cobalt acetate with nitrogen-containing long chain ligand,followed by thermal decomposition.The Co3O4 nanospheres as an anode have shown excellent electrochemical performance as an anode.Secondly,the Co3O4 nanoparticles which were rapidly synthesized through cobalt oleate as precursor,have possessed high specific capacity and longer cycle life.Thirdly,the Co-containing MOF materials(Co-MOF)were directly utlized as the anode with superior electrochemical performance.(3)Study on catalytic oxidation performance:Firstly,CuO and CuO/Co3O4 nanoparticles,which were achieved via the thermal decomposition of coordination assembly of copper acetate,or and cobalt acetate with nitrogen-containing organic ligands respectively,have shown excellent catalytic performance in the oxidation of styrene with high yield for benzaldehyde and can be also recycled in mild conditions.Secondly,bi-MOF materials(Mn/Co-MOF)as catalyst were found to have good cycling stability for the oxidation of benzylamine,which can be completely converted to imine after 3 hours at room temperature.Thirdly,Pt nanowires were utilized as catalyst for reversible hydrogenation-oxidative dehydrogenation of quinolones with good yields and excellent cycling stability.