Enhanced visible light photoelectrochemical water splitting using nanotubular FeOx-TiO2 annealed at different temperatures

Nanostructured semiconductor photoelectrodes that can operate under renewable solar energy are of great interest for both fundamental studies and practical applications. In this paper, we studied the semiconducting and photoelectrochemical properties of nanotubular FeOx-TiO2 annealed at different temperatures. Nanostructured anodic titanium oxide layers were modified by impregnation with a solution containing 100 mM FeCl3 followed by their annealing at 400 degrees C, 500 degrees C, and 600 degrees C. The synthesized materials were characterized by using a field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and photoelectrochemical measurements. It was found that depending on the annealing temperature, the studied materials showed a different photoelectrochemical response. The lowest value of band gap was observed for the sample annealed at 500 degrees C, which is related to the presence of a mixture of anatase and rutile phases together with iron oxides.

Automated summary

This study investigated the semiconducting and photoelectrochemical properties of nanotubular FeOx-TiO2 annealed at different temperatures, revealing that the annealing temperature has an impact on the photoelectrochemical response of the materials, with the sample annealed at 500°C showing the lowest band gap value.