Abstract: Processes for forming films comprising multiple layers of nanostructured support elements are described. A first layer of nanostructured support elements is formed by depositing a base material on a substrate and annealing. Further growth of the first layer of nanostructures is then inhibited. Additional layers of nanostructured support elements may be grown on the first layer of nanostructures through additional deposition and annealing steps. The multilayer films provide increased surface area and are particularly useful in devices where catalyst activity is related to the surface area available to support catalyst particles.

Abstract: Processes for extending the length of nanostructured support elements of thin film layers are described. The processes involve the initial formation nanostructured support elements during a first annealing step. A coating of material is deposited on the nanostructured support elements. During a second annealing step the initially formed nanostructured support elements longitudinally extend. Longer nanostructured support elements provide increased surface area for supporting catalyst material, thus allowing higher catalyst loading across the layer. Layers having extended nanostructured support elements are particularly useful for electrochemical devices such as fuel cells where catalyst activity is related to the surface area available to support the catalyst.