Pt-Decorated g-CN/TiO Nanotube Arrays with Enhanced Visible-Light Photocatalytic Activity for H Evolution.

Aligned TiO nanotube layers (TiNTs) grown by self-organizing anodization of a Ti-substrate in a fluoride-based electrolyte were decorated with graphitic-phase CN (g-CN) via a facile chemical vapor deposition approach. In comparison with classical TiO nanotubes (anatase), the g-CN/TiNTs show an onset of the photocurrent at 2.4 eV (vs. 3.2 eV for anatase) with a considerably high photocurrent magnitude in the visible range. After further decoration with Pt nanoparticles, we obtained a visible-light responsive platform that showed, compared with g-CN-free TiNTs, a strong enhancement for photoelectrochemical and bias-free H evolution (15.62 μLh cm), which was almost a 98-fold increase in the H production rate of TiNTs (0.16 μLh cm). In a wider context, the g-CN-combined 3 D nanoporous/nanotubular structure thus provides a platform with significant visible-light response in photocatalytic applications.