A new study on formation mechanism of ordered porous anodized metal oxides

The preparation of ordered porous metal oxide films by anodic oxidation is an efficient and simple preparation method. However, there has been no unified explanation about the formation mechanism of the porous structure for many years. In this paper, the relationship between the crystal structure of metals and the morphology of ordered porous metal oxide films is proposed. The influence of the crystal structures of different metals on the optimal morphology of porous films is discussed. Systematic studies show that anodic metals with face‐centered cubic structure form highly ordered porous metal oxide films after anodic oxidation; metals with hexagonal dense arrangement form ordered nanotube arrays after anodic oxidation, but those with body‐centered cubic structure form poorly ordered porous films after anodic oxidation. These results provide a new perspective and theoretical framework for the preparation of ordered porous metal oxide films by anodic oxidation.