Efficient Photocatalytic H2 Evolution: Controlled Dewetting–Dealloying to Fabricate Site‐Selective High‐Activity Nanoporous Au Particles on Highly Ordered TiO2 Nanotube Arrays

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