Abstract
A novel Ti(3+) self-doped branched rutile TiO₂ 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 TiO₂ NRAs are determined. Using TiO₂ nanoparticles (NPs) deposited on the top of the nanorods as seeds, TiO₂ nanobranches can easily grow on the top of the nanorods. Moreover, the Ti(3+) defects in the TiO₂ NPs and associated oxygen vacancies, and the nanobranches expend the optical absorption edge of the TiO₂ NRAs from 400 nm to 510 nm. Branched TiO₂ NRAs exhibit excellent photoelectrochemical properties compared to the pure TiO₂ 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 TiO₂ NRAs will provide a new path to the fabrication of hierarchical nanostructured materials.