  In the present work we introduce a technique to form a photocatalyst, based
on Pt nanoparticles suspended over the mouth of TiO2 nanotubes. These
structures are obtained by the decoration of the top end of highly ordered TiO2
nanotubes with a web of TiO2 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 TiO2 nanotubes, show a strongly
enhanced photocatalytic H2 evolution efficiency.
