Enhanced Photoelectrochemical Properties of Ti(3+) Self-Doped Branched TiO(2) Nanorod Arrays with Visible Light Absorption

A novel Ti(3+) self-doped branched rutile TiO(2) nanorod arrays (NRAs) was successfully grown on an F-doped tin oxide (FTO) transparent conductive glass by a combined hydrothermal and magnetron sputtering method. Surface morphology, structure, optical properties, and photoelectrochemical behavior of the branched TiO(2) NRAs are determined. Using TiO(2) nanoparticles (NPs) deposited on the top of the nanorods as seeds, TiO(2) nanobranches can easily grow on the top of the nanorods. Moreover, the Ti(3+) defects in the TiO(2) NPs and associated oxygen vacancies, and the nanobranches expend the optical absorption edge of the TiO(2) NRAs from 400 nm to 510 nm. Branched TiO(2) NRAs exhibit excellent photoelectrochemical properties compared to the pure TiO(2) NRAs, as revealed by photoelectrochemical measurements. This enhanced photoelectrochemical properties is induced by the increased surface area and expanded optical absorption range. Due to their favorable characteristics, these novel branched TiO(2) NRAs will provide a new path to the fabrication of hierarchical nanostructured materials.