Double-Wall TiO 2 Nanotubes for Dye-Sensitized Solar Cells: A Study of Growth Mechanism
Journal
ACS Sustainable Chemistry and Engineering
Journal Volume
6
Journal Issue
3
Pages
3907-3915
Date Issued
2018
Author(s)
Abstract
One-dimensional TiO 2 nanotubes (TNTs) are promising semiconductor photoanodes for dye-sensitized solar cells (DSSCs) due to their rapid electron transportation property; however, the lack of high surface area restricts their application. Double-wall TiO 2 nanotubes (DWTNTs) were synthesized to compensate for the smaller surface area of single-wall TiO 2 nanotubes (SWTNTs) and the comprehensive growth mechanism of DWTNTs is clearly demonstrated in this study. The evolution of pores and pits in three dimensions causes the formation of DWTNTs. After optimizing the thickness of DWTNTs, the DSSC with DWTNTs on the flexible Ti substrate showed a higher power conversion efficiency (£b) of 6.90 ¡Ó 0.10%, as compared to that of the cell with SWTNTs (4.66 ¡Ó 0.15%), owing to a significant increase in the short-circuit photocurrent density caused by the higher surface area for dye adsorption for the former case. Electrochemical impedance spectroscopy, incident photon-to-electron conversion efficiency curves, and UV-vis absorption spectra were conducted to sustain the explanations. ? Copyright ? 2018 American Chemical Society.
Subjects
Anodization
Double-wall TiO 2 nanotubes
Dye-sensitized solar cell
Electrochemical impedance spectroscopy
Flexible photoanode
Incident photon-to-electron conversion efficiency
Type
journal article