Sodium Fluoride-Assisted Modulation of Anodized TiO<sub>2</sub> Nanotube for Dye-Sensitized Solar Cells Application
Jung-Ho Yun
Yun Hau Ng
Changhui Ye
Attila J. Mozer
Gordon G. Wallace
Rose Amal
10.1021/am200147b.s001
https://acs.figshare.com/articles/journal_contribution/Sodium_Fluoride_Assisted_Modulation_of_Anodized_TiO_sub_2_sub_Nanotube_for_Dye_Sensitized_Solar_Cells_Application/2648245
This work reports the use of sodium fluoride (in ethylene glycol
electrolyte) as the replacement of hydrofluoric acid and ammonium
fluoride to fabricate long and perpendicularly well-aligned TiO<sub>2</sub> nanotube (TNT) (up to 21 μm) using anodization. Anodizing
duration, applied voltage and electrolyte composition influenced the
geometry and surface morphologies of TNT. The growth mechanism of
TNT is interpreted by analyzing the current transient profile and
the total charge density generated during anodization. The system
with low water content (2 wt %) yielded a membrane-like mesoporous
TiO<sub>2</sub> film, whereas high anodizing voltage (70 V) resulted
in the unstable film of TNT arrays. An optimized condition using 5
wt % water content and 60 V of anodizing voltage gave a stable array
of nanotube with controllable length and pore diameter. Upon photoexcitation,
TNTs synthesized under this condition exhibited a slower charge recombination
rate as nanotube length increased. When made into <i>cis</i>-diisothiocyanato-bis(2,2̀-bipyridyl-4,4̀-dicarboxylato)
ruthenium(II) bis (tetrabutyl-ammonium)(N719) dye-sensitized solar
cells, good device efficiency at 3.33 % based on the optimized TNT
arrays was achieved with longer electron time compared with most mesoporous
TiO<sub>2</sub> films.
2011-05-25 00:00:00
60 V
electrolyte composition
surface morphologies
anodizing voltage
ethylene glycol electrolyte
nanotube length
device efficiency
charge recombination rate
electron time
optimized TNT arrays
pore diameter
charge density
growth mechanism
TNT arrays
sodium fluoride
Anodized TiO 2 Nanotube
mesoporous TiO 2 films
Anodizing duration
optimized condition
21 μ m
ammonium fluoride
hydrofluoric acid