Oxygen bubble mould effect: serrated nanopore formation and porous alumina growth

We discovered a unique formation of serrated nanopore in porous anodic alumina (PAA). A new growth model is proposed for the formation mechanism of PAA. The model emphasizes the close relationship between pore generation and oxygen evolution. The initial pore formation is ascribed to oxygen bubble mould effect. Our model provides a satisfactory explanation for the growth process of PAA, alleviating the difficulties encountered in existing theories. These findings represent a decisive new step towards the full understanding of the nature of PAA films. The serrated nanopore arrays in PAA could also be used in a wide range of future nanostructure fabrications.