Noble metals on anodic TiO2 nanotubes mouths: Thermal dewetting of   minimal Pt co-catalyst loading leads to significantly enhanced photocatalytic   H2 generation
  The least is the best. We introduce a technique to strongly reduce Pt use for photocatalytic hydrogen generation from TiO2 nanotubes. By site-selectively depositing thin layers of Pt only at the mouth of the nanotubes and by a subsequent thermal dewetting step, we achieve an outstanding photocatalytic improvement with minimal amounts of co-catalyst. 
Nhat Truong Nguyen, Marco Altomare, JeongEun Yoo, Nicola Taccardi,   Patrik Schmuki
physics.chem-ph