TiO2 nanorods and semi-nanotubes prepared from anodic aluminum oxide template and their applications as photoelectrodes in dye-sensitized solar cells

Abstract

Anodic aluminum oxide (AAO) was used as a template coupled with liquid process for synthesis of TiO2 nanorods and seminanotubes. Immersion setting (IS) and vacuum drop setting (VDS) were carried out to insert a TiO2 precursor solution into AAO pores. With the calcination and NaOH aq. treatment to remove AAO, scanning electron microscopy (SEM) revealed that TiO2 nanorods with diameter around 100-200 nm were successfully fabricated from IS, whereas TiO2 semi-nanotubes were given from VDS. The synthesized nanorods or semi-nanotubes were mixed with commercial TiO2 nanoparticles (P-25) with mixing ratios of 5:95, 10:90 and 15:85 (by mass). The optimum mixing ratios for nanorods and semi-nanotubes are 5:95 and 10:90, respectively. The photoelectrodes made with nanorods or semi-nanotubes showed better performances than the cells used of only P-25, because of the effects of one-dimensional (1-D) nanostructure.