Designing efficient and stable water splitting photocatalysts is an intriguing challenge for energy conversion systems. We report on the optimal fabrication of perfectly aligned nanotubes on trimetallic Ti-Mo-Fe alloy with different compositions prepared via the combination of metallurgical control and facile electrochemical anodization in organic media. The X-ray diffraction (XRD) patterns revealed the presence of composite oxides of anatase TiO2and magnetite Fe3O4with better stability and crystallinity. With the optimal alloy composition Ti-(5.0 atom %) Mo-(5.0 atom %) Fe anodized for 16 h, enhanced conductivity, improved photocatalytic performance, and remarkable stability were achieved in comparison with Ti-(3.0 atom %) Mo-(1.0 atom %) Fe samples. Such optimized nanotube films attained an enhanced photocatalytic activity of ∼0.272 mA/cm2at 0.9 VSCE, which is approximately 4 times compared to the bare TiO2nanotubes fabricated under the same conditions (∼0.041 mA/cm2at 0.9 VSCE). That was mainly correlated with the emergence of Mo and Fe impurities within the lattice, providing excess charge carriers. Meanwhile, the nanotubes showed outstanding stability with a longer electron lifetime. Moreover, carrier density variations, lower charge transfer resistance, and charge carriers dynamics features were demonstrated via the Mott-Schottky and electrochemical impedance analyses
