In the present work, self-ordered MoO3-TiO2 nanotube layers have been fabricated from Ti-Mo (7 wt.% Mo) alloy through anodization, and characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and photoelectrochemical measurements. In comparison with pure TiO2 nanotubes, the synthesized MoO3-TiO2 nanotubes showed an enhanced donor concentration, lower electron transfer resistance, and longer electron lifetime. Moreover, photoinduced-carrier-separation efficiency also improved remarkably on addition of MoO3 to the TiO2 nanotube matrix. It was also shown that these beneficial properties led to higher photocatalytic water splitting activity and photocurrent response in the MoO3-TiO2 nanotubes. (C) 2015 Elsevier B.V. All rights reserved.