High aspect ratio self ordered alumina nanotubes, SEM and EDX characterization

Abstract

Alumina nanotube and porous membranes were fabricated by anodic oxidation of 99.99 % aluminum foils in aqueous electrolytes containing orthophosphoric acids and nickel sulfate hydrate. This way, nanotubes and porous alumina membranes can be obtained in compact packing. Wall thickness, membrane thickness and pore diameter can be easily controlled by correct adjustment of solution composition, anodic oxidation time and the values of voltage and current applied. The membranes obtained as described are amorphous. The crystalline phases can be obtained as a result of a subsequent thermal treatment.