Preparation and Photoelectrochemical Activity of Cr-Doped TiO2 Nanorods with Nanocavities

Cr-doped TiO2 nanorods with nanocavities were synthesized by a facile hydrothermal treatment and heating in air. The samples were characterized respectively by means of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). XRD patterns indicated that all the samples were anatase crystalline. HRTEM results and the electron diffraction patterns illustrated that the TiO2 nanorods possessed the single-crystalline Structure. TEM images confirmed that there were different types of nanocavities inside the nanorods, Such as a circle, hexagon, and rectangle. XPS results Suggested that Cr elements were Successfully doped into the TiO2 nanorods after hydrothermal and most Cr congregated on the Surface in the form of Cr2O3 after heating. The optical properties of the samples were Studied with a UV-vis spectrometer. The photoelectrochemical activity of the Cr-doped TiO2 nanorods thin film was better than that of the commercial anatase TiO2 particulate thin film. The high photoelectrochemical activity of the synthesized Cr-doped TiO2 nanorods could be attributed to three factors: the doped Cr, one-dimensional nanostructure of the nanorod, and the increased light-harvesting abilities.