Photoelectrochemical characteristics of TiO₂ nanorod arrays grown on fluorine doped tin oxide substrates by the facile seeding layer assisted hydrothermal method

Abstract

TiO₂ nanorod arrays (NRAs) were prepared on fluorine doped tin oxide (FTO) substrates by a facile two-step hydrothermal method. The nanorods were selectively grown on the FTO regions which were covered with TiO₂ seeding layer. It took 5 h to obtain the compact arrays with the nanorod length of ~2 μm and diameter of ~50 nm. The photoelectrochemical (PEC) properties of TiO₂ NRAs are also investigated. It is demonstrated that the TiO₂ NRAs indicate the good photoelectric conversion ability with an efficiency of 0.22% at a full-wavelength irradiation. A photocurrent density of 0.21 mA/cm² is observed at 0.7 V versus the saturated calomel electrode (SCE). More evidences suggest that the charge transferring resistance is lowered at an irradiation, while the flat-band potential (V_fb) is shifted towards the positive side.