Surface-phase junctions of branched TiO2 nanorod arrays for efficient photoelectrochemical water splitting

Flower-like branched TiO2 nanorod arrays (NRs) owning the surface anatase/rutile junctions on FTO substrates with operational diameter were successfully fabricated by a modified hydrothermal method. Transmission electron microscopy, Raman spectroscopy, field emission scanning electron microscopy, and X-ray diffraction revealed a unique flower-like ranched morphology, surface features, a crystal phase, and lattice constant of TiO2. Photoelectrochemical (PEC) measurements showed excellent photocatalytic properties of the flower-like branched TiO2 NRs. The surface phase formed between anatase and rutile TiO2 NRs which efficiently enhances the separation of photo-generated electron-hole pairs and accelerates the transport of charges is the key influence factor. The results suggest that the branched TiO2 NRs owning the surface anatase/rutile junctions are very promising platform to make highly efficient photoanodes for energy devices. (C) 2014 Elsevier B.V. All rights reserved.