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Using electrodeposition, composite method of solid state reaction to prepare zinc aluminate nano materials and research

Author: NiuGuoDong
Tutor: LiuJianXiong
School: Kunming University of Science and Technology
Course: Materials Processing Engineering
Keywords: Alumina template Zinc aluminate template Aluminum zinc nanotube Solid statereaction electrodeposition
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Type: Master's thesis
Year: 2013
Downloads: 21
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Abstract

Zinc aluminate spinel is a wide band gap (3.8eV) semiconductor material. It has been widely used in high-temperature ceramic materials, catalysts, and many other fields because of its high physical and chemical stability, such as its good thermal stability, corrosion resistance as well as its small expansion coefficient, high hardness, good dispersion,etc. With the preparation technology of zero-dimensional materials improving, one-dimensional nanomaterials (nanowires, nanotubes, etc.) have attracted more researchers’attention because of their special physical and chemical properties.The development status and commonly methods for preparing as well as their performance of nanomaterials were reviewed; the program of this research was proposed and the feasibility analysis was conducted, the required equipment of the testing characterization in the experiment processes was briefly introducted.The main research content is that the alumina template with a better degree of order is successfully prepared, using oxalic acid as the electrolyte with a two-step anodization method. Saturated SnC14solution is used to remove the back aluminum, and the phosphoric acid solution is used to drill and expand the nano-holes.and then a layer of is sputtered with the ion sputtering method on the back of the template,which is used as the conductive layer for the electrodeposition of zinc nanowires.In the end of this chapter, the formation mechanism of the ordered alumina templates is analyzed, the problems is proposed during the preparation and the solutions are given.Zinc oxide nanowires and alumina template were used as the raw materials, adopted solid state reaction method and the Kirkendall effect, successfully prepared zinc aluminate nano-template. The Zn nanowires are assembled in the alumina template at first, the Zn nanowires are oxidized to zinc oxide nanowires through the low-temperature annealing for40hours, and then the sample is annealed treatment at high-temperature, zinc aluminate structure is obtained via the solid-state reaction between the zinc oxide nanowires and alumina template. The unequal diffusion reaction between zinc atoms and aluminum atoms at the interfaces (Kirkendall effect), leading to the regeneration of hollow nano-pores at the original location of the zinc oxide in the solid-state reaction process, and finally the unreacted zinc oxide is removed by NaOH solution corrosion, the nanoscale zinc aluminate template is obtained.Successfully prepared zinc aluminate nanotubes through using the template method and solid-state reaction method. Zinc nanowires is electrodeposited in the alumina template first. Zinc is changed to zinc oxide to keep tempurature at350℃for40hours at the second step. The sample is annealed700℃for a certain period of time, solid state diffusion reaction is conducted between zinc oxide and alumina, and the zinc aluminate nanotube is formed at this stage. The fourth step is the etching process, the unreacted zinc oxide and alumina substrate is etched, and finally obtained the nano-tube structure.

Using electrodeposition, composite method of solid state reaction to prepare zinc aluminate nano materials and research

Abstract

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