Octagraphene as a versatile carbon atomic sheet for novel nanotubes, unconventional fullerenes, and hydrogen storage

Abstract

We study a versatile structurally favorable periodic sp 2 -bonded carbon atomic planar sheet with C 4v symmetry by means of the first-principles calculations. This carbon allotrope is composed of carbon octagons and squares with two bond lengths and is thus dubbed as octagraphene. It is a semimetal with the Fermi surface consisting of one hole and one electron pocket, whose low-energy physics can be well described by a tight-binding model of π-electrons. Its Young's modulus, breaking strength and Poisson's ratio are obtained to be 306 N/m, 34.4 N/m and 0.13, respectively, which are close to those of graphene. The novel sawtooth and armchair carbon nanotubes as well as unconventional fullerenes can also be constructed from octagraphene. It is found that the Ti-absorbed octagraphene can be allowed for hydrogen storage with capacity around 7.76 wt%.

Fullerenes with Heptagonal Rings An Overview

“…We can observe in Figure 1 that, as it was mentioned previously besides heptagons, some nonclassical fullerenes may contain squares, and even octagons: Xian-Lei Sheng et al [10].…”

Распространение Электромагнитных Волн В Электропроводящих Графеноподобных Углеродных Наноаллотропах

“…Рассматриваются лишь s p 2 -наноаллотрпы, в которых имеются свободные электроны. Следует от-метить, что существование указанных структур при комнатной температуре и их термодинамическая устой-чивость пока предсказаны теоретически, однако фи-зические свойства и возможные практические при-менения этих альтернативных классическому графе-ну двумерных наноаллотропов углерода в послед-нее время интенсивно изучаются [8][9][10][11][12][13]. В частно-сти, большое внимание уделяется так называемому октаграфену или T-графену, обозначенному здесь как (C) 44 [9,10,12].…”

Hypothetical planar and nanotubular crystalline structures with five interatomic bonds of Kepler nets type

“…The cited 9,[37][38][39][40][41][42] for comparison values of some parameters for known types of 2D crystals and nanotubes are given in Table III.…”

“…The maximum magnitude (375 N/m for phosphorus KC in the form ) slightly large then corresponding for graphene and octagraphene. 9 Obviously due to the atoms located at the vertices of triangles and squares (Fig. 2c).…”

“…One of them, 48 2 , is realized in the structure of octagraphene. 9 It is shown on second line (second picture) in Fig. 1.…”