Abstract
Aligned TiO2 nanotube layers (TiNTs) grown by self-organizing anodization of a Ti-substrate in a fluoride-based electrolyte were decorated with graphitic-phase C3N4 (g-C3N4) via a facile chemical vapor deposition approach. In comparison with classical TiO2 nanotubes (anatase), the g-C3N4/TiNTs show an onset of the photocurrent at 2.4eV (vs. 3.2eV 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-C3N4-free TiNTs, a strong enhancement for photoelectrochemical and bias-free H-2 evolution (15.62 mu Lh(-1) cm(-2)), which was almost a 98-fold increase in the H-2 production rate of TiNTs (0.16 mu Lh(-1) cm(-2)). In a wider context, the g-C3N4-combined 3D nanoporous/nanotubular structure thus provides a platform with significant visible-light response in photocatalytic applications.