title: Dopant-specific unzipping of carbon nanotubes for intact crystalline graphene nanostructures.
abstract: Atomic level engineering of graphene-based materials is in high demand to enable customize structures and properties for different applications. Unzipping of the graphene plane is a potential means to this end, but uncontrollable damage of the two-dimensional crystalline framework during harsh unzipping reaction has remained a key challenge. Here we present heteroatom dopant-specific unzipping of carbon nanotubes as a reliable and controllable route to customized intact crystalline graphene-based nanostructures. Substitutional pyridinic nitrogen dopant sites at carbon nanotubes can selectively initiate the unzipping of graphene side walls at a relatively low electrochemical potential (0.6 V). The resultant nanostructures consisting of unzipped graphene nanoribbons wrapping around carbon nanotube cores maintain the intact two-dimensional crystallinity with well-defined atomic configuration at the unzipped edges. Large surface area and robust electrical connectivity of the synergistic nanostructure demonstrate ultrahigh-power supercapacitor performance, which can serve for AC filtering with the record high rate capability of -85° of phase angle at 120 Hz.
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Joonwon
authors.initials: J
authors.lastname: Lim
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Uday Narayan
authors.initials: UN
authors.lastname: Maiti
authors.affiliation: Graduate School of Nanoscience and Technology, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Na-Young
authors.initials: NY
authors.lastname: Kim
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Rekha
authors.initials: R
authors.lastname: Narayan
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Dong Sung
authors.initials: DS
authors.lastname: Choi
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Youngtak
authors.initials: Y
authors.lastname: Oh
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Ju Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Gil Yong
authors.initials: GY
authors.lastname: Lee
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Seok Hun
authors.initials: SH
authors.lastname: Kang
authors.affiliation: Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Hyunwoo
authors.initials: H
authors.lastname: Kim
authors.affiliation: Graduate School of Nanoscience and Technology, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Yong-Hyun
authors.initials: YH
authors.lastname: Kim
authors.affiliation: National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors.forename: Sang Ouk
authors.initials: SO
authors.lastname: Kim