Nature of Graphene Edges: A Review

Abstract

Graphene edges determine the optical, magnetic, electrical, and electronic properties of graphene. In particular, termination, chemical functionalization and reconstruction of graphene edges leads to crucial changes in the properties of graphene, so control of the edges is critical to the development of applications in electronics, spintronics and optoelectronics. Up to date, significant advances in studying graphene edges have directed various smart ways of controlling the edge morphology. Though, it still remains as a major challenge since even minor deviations from the ideal shape of the edges significantly deteriorate the material properties. In this review, we discuss the fundamental edge configurations together with the role of various types of edge defects and their effects on graphene properties. Indeed, we highlight major demanding challenges to find the most suitable technique to characterize graphene edges for numerous device applications such as transistors, sensors, actuators, solar cells, light-emitting displays, and batteries in graphene technology.

Electronic and Magnetic Properties of Zigzag Boron-Nitride Nanoribbons with Even and Odd-Line Stone-Wales (5–7 Pair) Defects

“…5 Between the zigzag (z) and armchair-edged NRs, zigzagedged NRs are more interesting because of the presence of enhanced local-density of states near the Fermi-level, which in turn arise because of the localized electronic states at their edges. 6 Also, as proved by the previous studies on zGNRs 5,8,9 and zBNNRs, 3,10,11 these edge states can be tuned using different methods, namely, passivation, doping, substitution, application of external electric fields, and so on, to achieve tunable electronic and magnetic properties in these ribbons. Even, half-metallicity has been predicted in both zGNRs 7,8,12 and zBNNRs 1−3,13 under different conditions.…”

Coordination chemistry on carbon surfaces

“…Therefore, it is critically important that these characteristics be accurately determined and controlled [10]. The surface chemistry of sp 2 carbon materials is governed by basal and edge carbon atoms [11,12], as well as by the presence of defects (i.e., structural carbon vacancies, non-aromatic rings) [13]. These imperfections and defects along the edges of graphene layers are the most active sites owing to high densities of unpaired electrons.…”

“…Clusters with C 60 ligand. The first cluster coordinated to fullerene, [Ru 3 (CO) 9 ( 3 -2 , 2 , 2 -C 60 )], was synthesized in 1996 by thermal decarbonylation of [Ru 3 (CO) 12 ] in the presence of C 60 [507]. The X-ray diffraction shows that Ru atoms are 2 coordinated and positioned over the short C C bonds, the Ru C distances are in between 2.324(9) and 2.213(9)Å (Fig.…”

Effects of oxidation on the defect of reduced graphene oxides in graphene preparation

“…The preferential oxidation might be due to that the edges had a higher chemical reactivity than the surfaces because the edges brought unpaired electrons [26]. Accordingly, low KMnO 4 additions would only produce a few of graphene oxide, for example GO-1 and GO-2 in Fig.…”