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Scrutinizing Defects and Defect Density of Selenium‐Doped Graphene for High‐Efficiency Triiodide Reduction in Dye‐Sensitized Solar Cells
Author(s) -
Meng Xiangtong,
Yu Chang,
Song Xuedan,
Iocozzia James,
Hong Jiafu,
Rager Matthew,
Jin Huile,
Wang Shun,
Huang Longlong,
Qiu Jieshan,
Lin Zhiqun
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201801337
Subject(s) - triiodide , annealing (glass) , graphene , materials science , electrolyte , energy conversion efficiency , doping , dye sensitized solar cell , auxiliary electrode , electron transfer , chemical engineering , electrode , nanotechnology , chemistry , photochemistry , optoelectronics , metallurgy , engineering
Understanding the impact of the defects/defect density of electrocatalysts on the activity in the triiodide (I 3 − ) reduction reaction of dye‐sensitized solar cells (DSSCs) is indispensable for the design and construction of high‐efficiency counter electrodes (CEs). Active‐site‐enriched selenium‐doped graphene (SeG) was crafted by ball‐milling followed by high‐temperature annealing to yield abundant edge sites and fully activated basal planes. The density of defects within SeG can be tuned by adjusting the annealing temperature. The sample synthesized at an annealing temperature of 900 °C exhibited a superior response to the I 3 − reduction with a high conversion efficiency of 8.42 %, outperforming the Pt reference (7.88 %). Improved stability is also observed. DFT calculations showed the high catalytic activity of SeG over pure graphene is a result of the reduced ionization energy owing to incorporation of Se species, facilitating electron transfer at the electrode–electrolyte interface.