Porous alumina membrane are often used as templates for synthesizing nanowire arrays due to their well-defined pore structures, high pore densities and uniform pore sizes. In this study, porous alumina with pore diameters of 15-135 nm was prepared via a two-step anodization process using sulphuric acid and oxalic acid as electrolytes. The anodization process was carried out in the voltage range of 15V to 60 V, using pure aluminium foil as anode and platinum as cathode. Pore diameters, pore depths and the spacing between adjacent pores were carefully controlled by the anodizing conditions used. The morphologies and pore structures of the templates produced were studied using plan-view and cross-sectional scanning electron microscopy (SEM).
