  Overlaid self-ordering processes: we form anodic self-organized TiO2
nanostumps and exploit them for self-ordering dewetting of Au-Ag sputtered
films. This forms ordered particle configurations at tube top (crown position)
or bottom (ground position). By dealloying we then form, from minimal amount of
noble metal, porous Au nanoparticles that when in crown position allow for a
drastically improved photocatalytic H2 production compared with nanoparticles
produced by conventional dewetting processes.
