Synthesis Of One-Dimensional Functional Nanomaterials Using Alumina Membrane As Template

One-dimensional nanomaterials can be widely applied in many fields,such as solar energy conversion,chemical sensor,catalysis,absorption and separation due to its novel electrical,optical,magnetic,thermal and chemical properties.So,research on the preparation and properties of one-dimensional nanomaterials are very important and are one of the most exciting areas in materials science.Among the different fabrication methods,using porous alumina as template is one of the most efficacious methods to synthesize one-dimensional nanomaterials.The goal of the thesis is to provide a simple and convenient way for preparing various functional nanotube (nanorod)arrays at room temperature using alumina membrane as a nanoreactor,and investigate some new methods of the electrodeposition,chemical reduction to fabricate one-dimensional nanomaterials,and researche the relationship among the synthesis conditions,structures and properties of one-dimensional nanomaterials.Firstly,we tried to prepare the magnetism Fe-group alloys(Fe-Co,Fe-Ni,Co-Ni) and rare earth alloys(Co-Sin,Co-Nd,Ni-Nd)nanotubes using porous alumina membrane as the template.The products were characterized by transmission electron microscopy,selected-area electron diffraction,scanning electron microscopy,and X-ray powder diffraction.The amorphous Fe-group and rare earth alloys nanotubes with outer diameters of 250-320 nm and length up to 30μm were obtained.It is very easy to produce nanotubes by using mercury as cathode due to their unusual electrochemistry and physics properties.The possible mechanism for the nanotubes was discussed.What's more,the amorphous nanotubes can be crystallized after being heated,which can improve and change their properties.So electrodeposition with mercury cathod is one of the efficiency methods to fabricate the metal nanotubes.Secondly,the amorphous Co-Sm and Co-Ni alloys nanotubes with outer diameters of 250-320 nm or 350-40 nm,and length of 30μm are prepared by liquid-liquid reaction in the holes of porous alumina membrane with the reducing agent NaBH₄ and the aqueous solutions of different metal salt(Co²⁺and Sm³⁺,Co²⁺ and Ni²⁺)at room temperature.The products were characterized by transmission electron microscopy,selected-area electron diffraction,scanning electron microscopy, energy-dispersive X-ray spectrometer attached to the field emission scanning electron microscopy and X-ray powder diffraction.The gas can give out in the reducing reactions,which contributes to the formation of tubular products in the hole of alumna membrane.The method improves the way of prepare other inorganic nanotubes.Thirdly,using porous alumina as reaction vessel,we tried to prepare one-dimensional organic optical nanomaterials.The nanorod arrays of 8-hydroxy quinoline aluminium with the diameter of 220-250 nm and the length of 25μm and 8-hydroxy quinoline zinc with the diameter of 285-300 nm and the length of 20μm have been prepared at room temperature by liquid-liquid reaction with the encounter of 8-hydroxy quinoline molecule with Zn²⁺or Al³⁺,respectively.The products were characterized by X-ray powder diffraction,transmission electron microscopy, scanning electron microscopy and energy-dispersive X-ray spectrometer attached to the field emission scanning electron,which indicated that the structure of 8-hydroxy quinoline aluminium is crystal,but that of 8-hydroxy quinoline zinc is amorphous. Comparing with 8-hydroxy quinoline,as-obtained 8-hydroxy quinoline aluminium and 8-hydroxy quinoline zinc have much stronger fluorescence intensity with "blue-shift" in ethanol.