Abstract (EN):
The catalytic activity of single-wall carbon nanohorns (SWNH) as counter electrodes (CE) of dye-sensitized solar cells
(DSC) was studied for the iodide/triiodide redox reaction. The catalytic activities of SWNH and high surface SWNH
(HS-SWNH) obtained by partial oxidation of SWNH were assessed based on charge-transfer resistances (Rct) and
current¿voltage curves. A half-cell configuration was used, and CE performances were compared to CEs made of
carbon black (CB) and Pt. A CE assembled with HS-SWNH and mixed with 10 wt.% of hydroxyethyl cellulose (HEC) -
HS-SWNH/HEC was found to have the highest electrocatalytic activity (lowest Rct) among all the carbon-based CEs tested
when annealed at 180 C (Rct = 141 ¿ cm2
); however, a very thick film (several tens of mm) would be required in order to
perform comparably to a Pt CE. The annealing of such CE at higher temperatures (above 400 C) did not improve its
catalytic activity, contrary to the other studied carbonaceous CEs.
The redox catalytic activity of SWNH and HS-SWNH decorated with Pt was also studied on a half-cell configuration and
compared to that of Pt/CB and pristine Pt. The Pt/SWNH/HEC CE showed the highest electrocatalytic activity per mass of
Pt, needing just 50% of Pt load to yield the same electrocatalytic activity of a DSC equipped with a Pt CE, but having half
of its transparency. Additionally, applications in temperature-sensitive substrates are envisioned for the Pt/SWNH/HEC CE
due to the use of lower annealing temperatures.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
11
License type: