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Use of single‐wall carbon nanohorns as counter electrodes in dye‐sensitized solar cells
Author(s) -
Cruz Rui,
Brandão Lúcia,
Mendes Adélio
Publication year - 2012
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.2959
Subject(s) - triiodide , dye sensitized solar cell , catalysis , iodide , redox , auxiliary electrode , chemistry , annealing (glass) , electrochemistry , electrode , materials science , chemical engineering , nuclear chemistry , analytical chemistry (journal) , inorganic chemistry , organic chemistry , composite material , electrolyte , engineering
SUMMARY 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 ( R ct ) 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 R ct ) among all the carbon‐based CEs tested when annealed at 180 °C ( R ct = 141 Ω cm 2 ); however, a very thick film (several tens of µm) 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. Copyright © 2012 John Wiley & Sons, Ltd.