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Scrutinizing Defects and Defect Density of Selenium‐Doped Graphene for High‐Efficiency Triiodide Reduction in Dye‐Sensitized Solar Cells |
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| Authors: | Xiangtong Meng Prof. Chang Yu Dr. Xuedan Song James Iocozzia Jiafu Hong Matthew Rager Prof. Huile Jin Prof. Shun Wang Longlong Huang Prof. Jieshan Qiu Prof. Zhiqun Lin |
| Affiliation: | 1. State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian, Liaoning, P. R. China;2. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA;3. College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, P. R. China |
| Abstract: | Understanding the impact of the defects/defect density of electrocatalysts on the activity in the triiodide (I3?) 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 I3? 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. |
| Keywords: | defects dye-sensitized solar cells ionization energy selenium-doped graphene triiodide reduction |