Ni-doped TiO2 nanotubes photoanode for enhanced photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting hydrogen production provides a promising way for sustainable development. In this work, we prepared Ni-doped TiO2 (Ti–Ni–O) nanotubes through anodizing different Ti-Ni alloys and further annealing them at elevated temperatures, and reported their PEC water splitting performance. It was found that Ni doping could improve light absorption and facilitate separation of photo-excited electron-hole pair. The nanotubes fabricated on Ti-1 wt.% Ni alloy and annealed at 550 °C exhibited better PEC water splitting performance than those on Ti-10 wt.% Ni alloy. The photoconversion efficiency was 0.67%, which was 3.35 times the photoconversion efficiency of undoped TiO2. It demonstrated that it was feasible to fabricate high-performance Ti–Ni–O nanotubes on Ti-Ni alloys and used as photoanode for improving PEC water splitting.