'Suspended' Pt nanoparticles over TiO_2 nanotubes for enhanced photocatalytic H_2 evolutiont

摘要

In the present work we introduce a technique to form a photo-catalyst based on Pt nanoparticles suspended over the mouth of anodic TiO_2 nanotubes. These structures are obtained by decorating the top end of highly ordered TiO_2 nanotubes with a web of TiO_2 nanofibrils, followed by sputter deposition of a minimum amount of Pt. A subsequent thermal dewetting step forms 3-6 nm-sized Pt nanoparticles along the nanofibrils. These structures, when compared to conventional Pt decoration techniques of TiO_2 nanotubes, show strongly enhanced photocatalytic H_2 evolution efficiency.