High-performance dye-sensitized solar cells using edge-halogenated graphene nanoplatelets as counter electrodes. (April 2015)

• Record Type: Journal Article
• Authors: Jeon, In-Yup; Kim, Hong Mo; Choi, In Taek; Lim, Kimin; Ko, Jaejung; Kim, Jae Cheon; Choi, Hyun-Jung; Ju, Myung Jong; Lee, Jae-Joon; Kim, Hwan Kyu; Baek, Jong-Beom
• Is Part Of: Nano energy. Volume 13(2015:Apr.)
• Page Start: 336
• Page End: 345
• Publication Date: 2015-04
• Subjects: Ball-milling -- Halogenations -- Graphene nanoplatelets -- Dye-sensitized solar cells -- Counter electrode; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.02.037
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Edge-selectively halogenated graphene nanoplatelets (XGnPs, X=Cl, Br, and I) were prepared by the mechanochemically driven reaction between graphite and diatomic halogen molecules (Cl2, Br2 or I2 ). The contents of halogens (Cl, Br, and I) in XGnPs were 3.18, 1.77, and 0.66 at%, respectively, by X-ray photoelectron spectroscopy. The XGnPs as counter electrodes (CEs) showed remarkably enhanced electrocatalytic activities toward Co ( bpy ) 3 3 + reduction reaction in dye-sensitized solar cells (DSSCs) with an excellent electrochemical stability. Amongst XGnPs, IGnP-CE demonstrated the lowest charge-transfer resistance ( R ct ) of 0.46 Ω cm 2 at the CE/electrolyte interface. This value is much lower than that of Pt-CE (0.81 Ω cm 2 ). In addition, the DSSC with IGnP-CE had the highest fill factor (71.3%) and cell efficiency (10.31%), whereas those of DSSCs with Pt-CE were only 70.6% and 9.92%, respectively. Graphical abstract: Edge-selectively halogenated graphene nanoplatelets (XGnPs) as counter electrodes (CEs) in DSSCs display superior electrocatalytic performance toward Co ( bpy ) 3 3 + reduction reaction to platinum (Pt) CE. The remarkably enhanced electrocatalytic performance is stemmed from low charge-transfer resistance at the interface of XGnP/electrolyte CEs. Highlights: Edge-halogenated graphene nanoplatelets (XGnPs, X=Cl, Br, I) are prepared for DSSC. IGnP-CE shows lower charge-transfer resistance (0.46 Ω cm 2 ) than that of Pt-CE (0.81 Ω cm 2 ). The DSSC device with IGnP-CE shows the higher fill factor (71.3%) than Pt-CE (70.0%). The cell efficiency of IGnP-CE (10.42%) is superior to that of Pt-CE (10.01%).