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

Xiangtong Meng; Chang Yu; Xuedan Song; James Iocozzia; Jiafu Hong; Matthew Rager; Huile Jin; Shun Wang; Longlong Huang; Jieshan Qiu; Zhiqun Lin

doi:10.1002/anie.201801337

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

Angew Chem Int Ed Engl. 2018 Apr 16;57(17):4682-4686. doi: 10.1002/anie.201801337. Epub 2018 Mar 15.

Authors

Xiangtong Meng^{1

2}, Chang Yu¹, Xuedan Song¹, James Iocozzia², Jiafu Hong¹, Matthew Rager², Huile Jin³, Shun Wang³, Longlong Huang¹, Jieshan Qiu¹, Zhiqun Lin²

Affiliations

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, 116024, Liaoning, P. R. China.
² School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
³ College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, Zhejiang, P. R. China.

PMID: 29488308
DOI: 10.1002/anie.201801337

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.

Publication types

Research Support, Non-U.S. Gov't