A novel method for fabricating self-ordered porous anodic alumina with wide interpore distance using phosphoric/oxalic acid mixed electrolyte.

A novel method for fabricating highly ordered porous anodic alumina (PAA) with continuously tunable interpore distance using phosphoric/oxalic acid mixed electrolyte was presented. PAA films with different pore diameters and interpore distances were fabricated by changing anodizing potential and concentration of oxalic acid, characterized by field emission scanning electron microscope (FESEM). Experimental results showed oxalic acid in mixed electrolyte could not only suppress the breakdown of PAA at high potential but also enlarge the continuously tunable interpore distance from 300 to 500 nm. The proportionality constant between interpore distance and anodizing potential is 2.48 at the potential from 180 to 200 V, 2.31 at the potential from 130 to 170 V. The optimal content of oxalic acid and potential has a second power function relationship. Our results could extend the applications of PAA templates in ordered nano-material fabrication field. [ABSTRACT FROM AUTHOR]