Scrutinizing Defects and Defect Density of Selenium‐Doped Graphene for High‐Efficiency Triiodide Reduction in Dye‐Sensitized Solar Cells

• DOI: 10.1002/ange.201801337
• Publication Date: 2018-02-28T03:09:12Z
• Authors: Xiangtong Meng; Chang Yu; Xuedan Song; James Iocozzia; Jiafu Hong; Matthew Rager; Huile Jin; Shun Wang; Longlong Huang; Jieshan Qiu; Zhiqun Lin
• Keywords: Triiodide; Auxiliary electrode

Abstract Understanding the impact of defects/defect density electrocatalysts on activity in triiodide (I 3 − ) reduction reaction dye‐sensitized solar cells (DSSCs) is indispensable for design and construction high‐efficiency counter electrodes (CEs). Active‐site‐enriched selenium‐doped graphene (SeG) was crafted by ball‐milling followed high‐temperature annealing to yield abundant edge sites fully activated basal planes. The defects within SeG can be tuned adjusting temperature. sample synthesized at an temperature 900 °C exhibited a superior response I with high conversion efficiency 8.42 %, outperforming Pt reference (7.88 %). Improved stability also observed. DFT calculations showed catalytic over pure result reduced ionization energy owing incorporation Se species, facilitating electron transfer electrode–electrolyte interface.