Preparation of NanoPorous Alumina by Anodization Method and Study of Their Structural Properties

Abstract

Highly ordered nanoporous alumina structures have been prepared by electrochemical anodization for high purity Al-foils, electrolyte cell parameters have controlled to obtain optimum preparation conditions. Anodization potential, current density and electrolyte concentration effects on the prepared porous layer, surface morphology have been studied by scanning electron microscope and energy dispersive x-ray spectroscopy have used to analyze chemical composition of the samples.Results of the SEM show that the pore size was about 20-80 nm and it depends strongly on the anodization potential & electrolyte concentration, the higher anodization potential can destroy the barrier layer & cause a hi-dissolution rate of aluminum in the electrolyte, while with low potential a porous layer cannot be obtained. The highest degree of order and hexagonal distribution of pores was obtained with anodization potential of 20 volts and 0.2M of the electrolyte concentration. Results of EDS confirm the formation of the aluminum oxide layer with traces of sulfur which belong to the electrolyte.