Abstract

• The formation of TiO2 nanotubes arrays were investigated in different electrolyte solutions. Three nanomaterials of TiO2 were prepared by electrochemical anodization using three different electrolyte solutions:0.5 wt.% NH4F with 4 wt.%, 6 wt.%, and 8wt.% of distilled water in ethylene glycol. SEM showed different morphologies caused by the variation in the water content of the solutions. By a change of the crystalline phase of the TiO2 nanotubes, the oxygen vacancies increased and affected to the optical and electrical properties of TiO2 nanotubes. To understand the interplay between the photoactivity and light absorption of TiO2 nanotubes annealed at 300℃, incident-photon-to-current-efficiency of TiO2 nanotubes was investigated as the function of the wavelength of incident light. IPCE% is a better parameter reflecting the spectral dependent photon response of TiO2 nanotubes.