Enhanced photoelectrochemical performance and charge transfer properties in self-organized NiOx-doped TiO2 nanotubes

In this present work, 5 wt% NiOx-doped TiO2 nanotubes with 8 μm thickness were fabricated by anodization from Ti-Ni alloy. After the characterization of SEM, XRD, XPS and electrochemical measurements, the doped nanotube structure shows a strongly enhanced electrochemical performances in conductivity, donor concentration and OH− ion intercalation ability. In order to better understand the effects of NiOx doping on mechanism of photoinduced carriers’ transfer, the photovoltaic performances were investigated by Transient Photovoltage (TPV) and Surface Photovoltage (SPV) techniques. It is interesting to find that the doped one exhibits a strong photoresponse in visible region and high photovoltage intensity. These results indicated that the incorporation of NiOx promoted the charge separation and inhibited recombination of photoinduced carriers in TiO2 nanotube.