Fabrication of porous alumina templates with a large-scale tunable interpore distance in a H2C2O4-C2H5OH-H2O solution

Highly ordered porous alumina templates with a large-scale tunable interpore distance (100–445 nm) have been successfully fabricated under an electric field of 40–180 V by modifying oxalic acid solution with adequate alcohol. The results under our experimental conditions show that the phenomena of burning and breakdown during the high-field anodization process can be avoided by adding a proper amount of alcohol to the oxalic acid solution. An excellent linear relationship between interpore distance and anodization voltage is obtained under 40–170 V, and the maximum anodization voltage that could be used to avoid burning and breakdown is 180 V.