title: Facile, scalable synthesis of edge-halogenated graphene nanoplatelets as efficient metal-free eletrocatalysts for oxygen reduction reaction.
abstract: A series of edge-selectively halogenated (X = Cl, Br, I) graphene nanoplatelets (XGnPs = ClGnP, BrGnP, IGnP) were prepared simply by ball-milling graphite in the presence of Cl2, Br2 and I2, respectively. High BET surface areas of 471, 579 and 662 m(2)/g were observed for ClGnP, BrGnP and IGnP, respectively, indicating a significant extent of delamination during the ball-milling and subsequent workup processes. The newly-developed XGnPs can be well dispersed in various solvents, and hence are solution processable. Furthermore, XGnPs showed remarkable electrocatalytic activities toward oxygen reduction reaction (ORR) with a high selectivity, good tolerance to methanol crossover/CO poisoning effects, and excellent long-term cycle stability. First-principle density-functional calculations revealed that halogenated graphene edges could provide decent adsorption sites for oxygen molecules, in a good agreement with the experimental observations.
authors.affiliation: Interdisciplinary School of Green Energy, Low-Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon, Ulsan, South Korea.
authors.forename: In-Yup
authors.initials: IY
authors.lastname: Jeon
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Choi
authors.forename: Min
authors.initials: M
authors.lastname: Choi
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Seo
authors.forename: Sun-Min
authors.initials: SM
authors.lastname: Jung
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
authors.forename: Lipeng
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Xia
authors.forename: Liming
authors.initials: L
authors.lastname: Dai
authors.forename: Noejung
authors.initials: N
authors.lastname: Park
authors.forename: Jong-Beom
authors.initials: JB
authors.lastname: Baek
mesh_terms: D002384:Catalysis; D006108:Graphite / Q000737:chemistry*; D054879:Halogenation; D006219:Halogens / Q000737:chemistry*; D000432:Methanol; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*
chemical_list: D006219:Halogens; D006108:Graphite; D010100:Oxygen; D000432:Methanol