Efficient Photocatalytic H2 Evolution: Controlled Dewetting-Dealloying   to Fabricate Site-Selective High-activity Nanoporous Au Particles on Highly   Ordered TiO2 Nanotube Arrays
  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. 
Nhat Truong Nguyen, Marco Altomare, JeongEun Yoo, Patrik Schmuki
cond-mat.mtrl-sci