Anodization of dual-layer laminated aluminum foils: A facile route to through-hole porous anodic alumina templates

Porous anodic alumina (PAA) film with through-hole structure has been widely employed as a template or host material for the development of nanostructures. However, the fabrication of complete through-hole PAA film in a controlled and reproducible way is still a challenge to date. Here, we report a facile method to fabricate the through-hole PAA templates. A dual-layer laminated aluminum foil rather than the generally used single-layer aluminum foil was employed to achieve this goal. The idea behind this approach is to transfer the oxide barrier layer to the second-layer foil of the dual-layer aluminum foil, thereby directly obtaining a PAA film with no barrier layer in the first-layer foil. A qualitative explanation for the transition behavior of anodization voltage of the dual-layer aluminum foil during galvanostatic anodization was given. Also, this study may aid a deeper understanding of the mechanism for PAA formation.