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.