Anodic Formation of Self‐Organized Cobalt Oxide Nanoporous Layers

Nanoporous materials: High-aspect-ratio, ordered porous Co3O4 layers were formed by self-organizing anodization of a cobalt substrate and subsequent annealing. The key for successful formation of such layers is to sufficiently suppress competing oxygen evolution during anodization. The aligned Co3O4 channel layers behave as a highly efficient water oxidation catalyst (see picture).