Facile synthesis and morphology control of bamboo-type TiO 2 nanotube arrays for high-efficiency dye-sensitized solar cells

Document Type

Article

Publication Date

7-12-2012

Abstract

We report fast synthesis of bamboo-type TiO 2 nanotube arrays via anodization of Ti in nonhazardous electrolyte under alternating voltage condition for applications as photoanodes in high-efficiency dye-sensitized solar cells (DSSCs). Formation mechanism of bamboo-type nanotubes is also explored. The low-voltage step reduces pH and ion-diffusion gradient inside TiO 2 nanotubes and induces formation of bamboo ridges on outer tube walls when a second high-voltage step is conducted. Ridge spacing and length of bamboo-type nanotubes can be facilely tuned by adjusting time of high-voltage step and electrolyte composition. All DSSCs based on bamboo-type TiO 2 nanotube arrays show higher efficiencies than those based on smooth-walled nanotubes with the same tube length due to enhanced surface area of bamboo-type nanotubes for dye loading. It is also noted that DSSC efficiency increases with the ridge density of bamboo-type nanotubes of the same length. For example, DSSC based on bamboo-type nanotubes (8 μm long) with the highest ridge density exhibits an efficiency of 5.64%, higher than the efficiency of 3.90% exhibited by DSSC based on smooth-walled nanotubes of the same length. Moreover, the DSSC efficiency can be further increased to 6.8% by growing significantly longer bamboo-type TiO 2 nanotubes (16.5 μm long) via decreasing water content in electrolyte. © 2012 American Chemical Society.

Publication Source (Journal or Book title)

Journal of Physical Chemistry C

First Page

14257

Last Page

14263

This document is currently not available here.

Share

COinS