Synthesis of well-ordered nanopores by anodizing aluminum foils in sulfuric acid

Well-ordered nanostructures were produced on industrial aluminum foils by one-, two-, and three-step anodizing processes performed in sulfuric acid at cell potentials between 15 and 25 V. Almost perfect triangular lattices of nanopores were obtained by the two- and three- step anodizing processes. It was found that the third step in the anodizing process neither significantly improves the ordering of the pores nor enlarges the size of the well-ordered domains. The effective growth rate of the oxide layer was calculated for various cell potentials and compared with literature data. The effect of the anodizing time on the ordering of pores and the size of the domains was established. The pore diameters and the interpore distances were evaluated for various cell potentials, too. Anodizing in sulfuric acid results in small pore sizes and interpore distances compared to the ones obtained by anodizing in phosphoric and oxalic acids. (C) 2002 The Electrochemical Society.