Fe-doped TiO2 nanorods with enhanced electrochemical properties as efficient photoanode materials

Abstract

Abstract Iron (Fe)-doped TiO 2 nanorods (NRs) photoanodes were grown as white, homogeneous film on fluorine doped tin oxide (FTO) substrates with various Fe-doping concentrations (0, 5, 7.5, and 10 mM) using the hydrothermal method. Scanning electron microscopy (SEM) image of the film shows dense and vertically aligned NR arrays. The consequence of Fe-doping, at increasing concentrations, on the structure optical and photoelectrochemical (PEC) properties of the TiO 2 NRs photoanodes were investigated. Charge accumulation processes and charge transfer characteristics were identified by electrochemical impedance spectroscopy. The donor density and the flat-band potential of the Fe-doping concentration were analyzed from the Mott-Schottky plot. The changes in the short circuit current (J sc ) and the open circuit voltage (V oc ) of the photoanodes are in relation with the electronic structure of the TiO 2 NRs. The ones doped with 5 mM of Fe display the highest photocurrent (0.55 mA).