Self-organized porous WO3 formed in NaF electrolytes

In the present work we show that by anodization of W in NaF electrolytes porous tungsten oxide layers can be formed under a range of experimental conditions. The morphology of the layers depends strongly on the NaF concentration as well as the formation potential. Under optimized electrochemical conditions self-organized porous tungsten oxide layers can be formed. The single pore openings are very regular and have an average pore diameter of 100 nm.