The effect of sulphuric acid and oxalic acid on the formation of anodic aluminium oxide templates using two-step anodization method

Abstract

The prevention of corrosion on the surface of aluminum by formation of a thin coating layer using anodization methods for enhanced applications is an active area of research. In this study, the fabrication of nanoporous anodic aluminum oxide (AAO) templates was performed by a two-step anodization process using aluminum with 99.98% purity in 0.3 M solution of oxalic acid or 0.1, 0.3, or 0.5 M solutions of sulfuric acid as electrolyte. Anodizing time, electrolyte solution and concentration, and current were found to be the main factors determining the pore diameter and interpore size. In addition, the voltage affected the number of pores on the AAO template. The structural features of the nanoporous templates were examined by scanning electron microscopy. The optimum conditions were determined to be 0.3 M sulfuric acid at 25 V.