title: Monolithic graphene oxide sheets with controllable composition.
abstract: Graphene oxide potentially has multiple applications and is typically prepared by solution-based chemical means. To date, the synthesis of a monolithic form of graphene oxide that is crucial to the precision assembly of graphene-based devices has not been achieved. Here we report the physical approach to produce monolithic graphene oxide sheets on copper foil using solid carbon, with tunable oxygen-to-carbon composition. Experimental and theoretical studies show that the copper foil provides an effective pathway for carbon diffusion, trapping the oxygen species dissolved in copper and enabling the formation of monolithic graphene oxide sheets. Unlike chemically derived graphene oxide, the as-synthesized graphene oxide sheets are electrically active, and the oxygen-to-carbon composition can be tuned during the synthesis process. As a result, the resulting graphene oxide sheets exhibit tunable bandgap energy and electronic properties. Our solution-free, physical approach may provide a path to a new class of monolithic, two-dimensional chemically modified carbon sheets.
authors.affiliation: 1] School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [2].
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Chu
authors.affiliation: 1] School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [2].
authors.forename: Jinsung
authors.initials: J
authors.lastname: Kwak
authors.affiliation: 1] Department of Materials Science and Engineering, Seoul National University, Seoul 151-742, Republic of Korea [2] Advanced Characterization and Analysis Group, Korea Institute of Materials Science, Changwon 642-831, Republic of Korea.
authors.forename: Sung-Dae
authors.initials: SD
authors.lastname: Kim
authors.affiliation: School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Mi Jin
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Soon-Dong
authors.initials: SD
authors.lastname: Park
authors.affiliation: School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Jae-Kyung
authors.initials: JK
authors.lastname: Choi
authors.affiliation: School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Gyeong Hee
authors.initials: GH
authors.lastname: Ryu
authors.affiliation: 1] School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [2] Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [3] Opto-Electronics Convergence Group and Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Kibog
authors.initials: K
authors.lastname: Park
authors.affiliation: 1] School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [2] Opto-Electronics Convergence Group and Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Sung Youb
authors.initials: SY
authors.lastname: Kim
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: 1] School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [2] Opto-Electronics Convergence Group and Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Zonghoon
authors.initials: Z
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Young-Woon
authors.initials: YW
authors.lastname: Kim
authors.affiliation: 1] School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [2] School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea [3] Opto-Electronics Convergence Group and Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Soon-Yong
authors.initials: SY
authors.lastname: Kwon