Study on the formation process of titania nanohole arrays

We try to clarify the formation mechanism of the titania nanohole array. In the process of synthesis of the titania nanohole array, two different reactions occur at once: one is the dissolution of the anodic alumina as a starting material and the other is the deposition of the titania powder. Since the initial dissolution rate of anodic alumina is faster than the initial deposition rate of titania, the sample weight first decreases. After the concentration of aluminum in the treatment solution became higher, the deposition rate of titania became faster than the dissolution rate of anodic alumina. During the formation process, the remaining anodic alumina formed the scaffolds. This mechanism could be applied to the formation process of other oxide nanohole array.