Abstract:
The large-scale,highly-ordered,vertically-oriented free-standing TiO
2 nanotube membranes were fabricated by three-step anodization Ti foils in ethylene glycol containing 0.25w(NH4F)%.Then the as-prepared free-standing membranes were transferred to FTO-coated glass substrates with TiO
2 sol,and the transparent TiO
2/FTO photoelectrode was obtained after annealing treatment.The morphologies,crystalline phase,optical properties were characterized using FE-SEM,XRD and UV-Vis-NIR spectrophotometer,respectively.To some extent,the structural parameters of the free-standing TiO
2 nanotube membranes(inner diameter,nanotube length,and wall thickness)are controllable.After the membranes were transferred onto the FTO-coated glass substrate,we can obtain the high quality and multi-application TiO
2/FTO photoelectrode.At the same time,it is found that the optical energy gap(
Eg) of TiO
2 nanotube membranes could be effectively modulated by different anodic oxidation voltage.Obviously,this work would be beneficial to apply in organic-inorganic photovoltaic devices.