Nanoporous Anodic Alumina with Hexagonal Ordering

Nanoporous Anodic Alumina has received significant attention of the world researchers as a template for the low cost fabrication of nanostructures of metals, semiconductors, polymers, superconductors, etc. In the present work it has been demonstrated that the type of electropolishing pre-treatment and the resulting nano-features on aluminum surface can influence the hexagonal ordering of the pores developed during anodizing. Apart from improving the ordering quality the work has been extended to relate the photoluminescence with the ordering quality of anodic alumina, prepared at a given anodizing voltage. New templates have been prepared, based on sandwiched structures. The two layers for the sandwiched structures were prepared by complete anodization of aluminum sheet from opposite sides and by changing the anodizing conditions, forming a new superlattice. Employing anodic alumina as a template, elctrodeposition of nickel nanowires in aqueous medium and in Dimethyl sulfoxide (DMSO) has been demosntrated. Silver nanowires have also been grown in the template with electrochemical (AC) and electroless deposition techniques.