title: Nitrogen-doped graphene nanoribbons as efficient metal-free electrocatalysts for oxygen reduction.
abstract: Nitrogen-doped graphene nanoribbon (N-GNR) nanomaterials with different nitrogen contents have been facilely prepared via high temperature pyrolysis of graphene nanoribbons (GNR)/polyaniline (PANI) composites. Here, the GNRs with excellent surface integration were prepared by longitudinally unzipping the multiwalled carbon nanotubes. With a high length-to-width ratio, the GNR sheets are prone to form a conductive network by connecting end-to-end to facilitate the transfer of electrons. Different amounts of PANI acting as a N source were deposited on the surface of GNRs via a layer-by-layer approach, resulting in the formation of N-GNR nanomaterials with different N contents after being pyrolyzed. Electrochemical characterizations reveal that the obtained N8.3-GNR nanomaterial has excellent catalytic activity toward an oxygen reduction reaction (ORR) in an alkaline electrolyte, including large kinetic-limiting current density and long-term stability as well as a desirable four-electron pathway for the formation of water. These superior properties make the N-GNR nanomaterials a promising kind of cathode catalyst for alkaline fuel cell applications.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University , Shanghai 200433, China.
authors.forename: Mingkai
authors.initials: M
authors.lastname: Liu
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Song
authors.forename: Sixin
authors.initials: S
authors.lastname: He
authors.forename: Weng Weei
authors.initials: WW
authors.lastname: Tjiu
authors.forename: Jisheng
authors.initials: J
authors.lastname: Pan
authors.forename: Yong-Yao
authors.initials: YY
authors.lastname: Xia
authors.forename: Tianxi
authors.initials: T
authors.lastname: Liu