Crystalline Graphene Nanoribbons with Atomically Smooth Edges via a Novel Physico- Chemical Route

A novel physico-chemical route to produce few layer graphene nanoribbons with atomically smooth edges is reported, via acid treatment (H2SO4:HNO3) followed by characteristic thermal shock processes involving extremely cold substances. Samples were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy. This method demonstrates the importance of having the nanotubes open ended for an efficient uniform unzipping along the nanotube axis. The average dimensions of these nanoribbons are approximately ca. 210 nm wide and consist of few layers, as observed by transmission electron microscopy. The produced nanoribbons exhibit different chiralities, as observed by high resolution transmission electron microscopy. This method is able to provide graphene nanoribbons with atomically smooth edges which could be used in various applications including sensors, gas adsorption materials, composite fillers, among others. A. Morelos-Gomez, K. Fujisawa, H. Muramatsu, T. Hayashi, Y. A. Kim and M. Endo are with the Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-853, Japan (e-mail: amorelos@shinshu-u.ac.jp, fujisawa@endomoribu.shinshu-u.ac.jp, muramatsu@endomoribu.shinshuu.ac.jp, hayashi@endomoribu.shinshu-u.ac.jp, yak@endomoribu.shinshuu.ac.jp, endo@endomoribu.shinshu-u.ac.jp). S. M. Vega-Díaz, F. Tristán-López, R. Cruz-Silva, H. Sakamoto, F. Khoerunnisa, K. Kaneko, M. Endo and M. Terrones are with Research Center for Exotic Nanocarbons (JST), Shinshu University, Wakasato 4-17-1, Nagano 380-8553, Japan (e-mail: sofia.mvega@gmail.com, ftristan@shinshu-u.ac.jp, rcruzsilva@shinshu-u.ac.jp, endo@endomoribu.shinshu-u.ac.jp, mtterrones@gmail.com) . V. J. González is with Departamento de Ciencia e Ingeniería de Materiales e Ingeniería Química, Universidad Carlos III. Av. Universidad 30, 28911 Leganés, Madrid, Spain (e-mail: vivianaj.gonzalez@gmail.com). Xi Miand, Yunfeng Shi and V. Meunier are with Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180-3590, USA (meuniv@rpi.edu). B. G. Sumpter is with Center for Nanophase Materials Sciences and Computer Science & Mathematics Division, Oak Ridge National Laboratory, P.O. Box 2008, MS6367, Oak Ridge (e-mail: sumpterbg@ornl.gov). V. Meunier is also with Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180-3590, USA. E. Muñoz-Sandoval is with Instituto de Microelectrónica de Madrid, IMM (CNM-CSIC), Newton 8, Tres Cantos, Spain. (e-mail: munozsandovalemilio314@gmail.com) M. Terrones is also with Department of Physics, Department of Materials Science and Engineering and Materials Research Institute. The Pennsylvania State University, 104 Davey Lab., University Park, Pennsylvania 16802, USA. E. Muñoz-Sandoval and V. J. González are on leave from the Advanced Materials Department, Instituto Potosino de Investigación Científica y Tecnológica, A.C., Camino a la Presa San José 2055, Col. Lomas 4a. sección, San Luis Potosí, SLP 78216, México.