Preparation And Characteristic Of Cobalt Nanocones Arrays

With the nanotechnology developing, 3D nonstructural materials become more attractive. Especially, the nanocones arrays materials have become hot-spot, for their special characteristic, such as the large surface area, high sensitivity to electrochemistry, good light diffusion and outstanding magnetic properties. Nowadays, most metal nanocones arrays materials are fabricated by AAO template-based method and LIGA photolithography, which are complicated and the manufacturing cost is high. What's more, the dimension of the structure is limited to the available templates. Here, we introduce a novel fabricating method, which named directional electrodepositing (DEP) is simple and easy for application. This method is considered as an ideal to manufacture metal nanocones arrays materials.The task of this thesis is studied around the target of fabricating cobalt nanocones arrays materials. Based on the traditional electrodepositing, the author developed this novel method of DEP to prepare the cobalt nanocones arrays without template. The structure of the products was subject to extensive structural characterization by X-ray diffraction (XRD), transmission electron microscope (TEM) and field-emitting scanning electron microscopes (FE-SEM), etc. The possible mechanism is provided and discussion. The main points are summarized as follows:1. Fabricating the cobalt nanocones arrays in the solution with inorganic additives using DEP method. With the use of DEP method and control the conditions of electrodepositing, cobalt nanocones arrays on copper substrate have been prepared. The result indicate that solution temperature and the concentration of crystallization conditioning agent are crucial to the formation of the nanocones arrays, which are averagely 200nm in root diameter and 600nm in height.2. With the method of DEP, the influence of five kinds of organic additives on the morphology of cobalt deposition has been researched. One of them is available to prepare cobalt nanocones arrays. The optimize conditions are: the concentration of crystalling condition agent 50g/l, solution temperature 45-55℃, pH=4.0, current density 10.0A/dm2. Investigation for control the morphologies of the aimed products performed by electrochemical test.3. The structure of the products was subject to extensive structural characterization by field-emitting scanning electro microscope (FE-SEM), X-ray diffraction (XRD) and Transmission Electron Microscope (TEM), etc. The outcome and possible mechanism author discussed show that crystals of cobalt are instantaneous nucleation in the initial stage of electrodepositing process, and grow along (110) for the effect of NH4+.