Advance in Close‐Edged Graphene Nanoribbon: Property Investigation and Structure Fabrication

Abstract

The absence of dangling bonds in close‐edged graphene nanoribbons (CEGNRs) confers upon them a series of fascinating properties, especially when compared with cylindrical carbon nanotubes and open‐edged GNRs. Here, the configuration of CEGNRs is described, followed by the structure‐related properties, including mechanical, thermal, electrical, optical, and magnetic properties. Based on the unique structures and extraordinary properties, their potential applications in a variety of fields, such as field‐effect transistors, energy suppliers, nanoactuators, and fibers, are discussed. Remarkably, the strategies applied for generating CEGNRs, mainly from the collapse of carbon nanotubes and graphene tubes, are depicted in detail. Finally, the prospects in the research area of CEGNRs are proposed.

Carbon nanotubes collapse phase diagram with arbitrary number of walls. Collapse modes and macroscopic analog

“…When d 0 >3nm, the vdW-LC approach (red line) shows a sharp decrease of P c , corresponding to a tube diameter where interactions between the PTM and the tube walls dominate, while the curvature energy is negligible for such diameters. SWCNT simulations (red circles), show a self-collapse diameter of 5.3 nm, in good agreement with the experimental data reported; about 5.1 nm is cited in the review of He et al [15]. This agreement allows then to fit γ F −C (see Table 1), in the vdW-LC model for SWCNT.…”

“…As expected, these points are mainly found in the collapsed domain. We have underlined a particular point from the work of He et al [15] (yellow square), which corresponds to the determination of the critical collapse diameter by observations of many SWCNT. This point should then lie on the limiting curve, and is found to be in very good agreement with the prediction of our model.…”

“…The many associated technological breakthroughs have opened perspectives in a broad range of applications, ranging from electronics [8,9], sensor developments [10],energy transport and storage [11,12,13] or biology and medical sciences such as drug delivery technology [14]. While both graphene and CNT sp 2 structures have concentrated an important part of the recent research efforts, there exist many hybrid structures between these two, which have been much less explored [15]. In the literature, they are referred as "collapsed nanotubes", "flattened carbon nanotubes", "closededge graphene nanoribbons" or "dogbones".…”

Intense Raman D Band without Disorder in Flattened Carbon Nanotubes

“…Furthermore, curvature on graphitic structures has been sometimes proposed as a hypothesis to explain an observed D band on graphene wrinkles, loops, and graphitic polyhedral crystals, while the contribution of topological defects could not be ruled out nor quantified. Flattened carbon nanotubes (FCNTs, scheme in Figure d) can be considered as few-layer graphene nanoribbons (GNRs) with continuity at the edges. − They overcome the as-yet unsolved difficulty to obtain scalable GNRs with atomically smooth edges, critical for electronics . To date there are very few reported Raman spectra of self-collapsed FCNTs, , and in these studies the objects were not identified as FCNTs but as GNRs.…”

Laser Irradiation-Hindered Growth of Small-Diameter Single-Walled Carbon Nanotubes by Chemical Vapor Deposition

“…As one of the new carbon nanomaterials, carbon nanotubes have been the focus of intensive research because of their fascinating structures and properties [1]. Particularly, singlewalled carbon nanotubes (SWNTs) possess extraordinary electrical and optical properties, rendering them exciting candidates for nanoelectronics and optoelectronics [2,3]. To realize the proposed applications of SWNTs, it is necessary to synthesize SWNTs with controlled orientation, density, diameter, and even chirality.…”