Nano-porous anodic aluminium oxide membranes with 6–19 nm pore diameters formed by a low-potential anodizing process

Self-organized nano-porous anodic aluminium oxide (AAO) membranes with small pore diameters were obtained by applying a low anodizing potential in sulfuric acid solutions. The pore diameters of the as-prepared AAO membranes were in the range of about 6–19 nm and the interpore distances were about 20–58 nm. Low potentials (6–18 V) were applied in anodizing processes to make such small pores. A linear relationship between the anodizing potential (Ua) and the interpore distance (Dint) was also revealed. By carefully monitoring the current density’s evolution as a function of time with different Ua (2–18 V) during the anodizing processes, a new formula is proposed to simulate the self-ordering anodizing process. (Some figures in this article are in colour only in the electronic version)