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Indexed by:期刊论文

Date of Publication:2018-01-01

Journal:Angewandte Chemie (International ed. in English)

Included Journals:PubMed、SCIE、EI

Volume:57

Issue:17

Page Number:4682-4686

ISSN No.:1521-3773

Key Words:defects; dye-sensitized solar cells; ionization energy; selenium-doped graphene; triiodide reduction

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. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.