Relation between Morphology and Photoelectrochemical Performance of TiO2 Nanotubes Arrays Grown in Ethylene Glycol/Water

The TiO2 nanotube films were prepared by anodizing Ti plates in 0.2 M NH4F ethylene glycol/10% H2O under different formation voltages keeping fixed the time length, or by keeping fixed the formation voltage and varying the time length. The morphology of the TiO2 film obtained was observed by SEM images and different morphological parameters were derived from them. Furthermore, the optical and semiconducting properties of TiO2 films were also measured. The photoelectrochemical performance toward water oxidation of the TiO2 only showed to be dependent with the inner diameter of the nanotubes, that could be related to the interaction of the film with the light and the transport of species in the electrolyte inward or outward the film.