Acetylene-Mediated Electron Transport in Nanostructured Graphene and Hexagonal Boron Nitride

Abstract

The discovery of graphene has catalyzed the search for other 2D carbon allotropes, such as graphynes, graphdiynes, and 2D π-conjugated polymers, which have been theoretically predicted or experimentally synthesized during the past decade. These materials exhibit a conductive nature bound to their π-conjugated sp 2 electronic system. Some cases include sp-hybridized moieties in their nanostructure, such as acetylenes in graphynes; however, these act merely as electronic couplers between the conducting π-orbitals of sp 2 centers. Herein, via first-principles calculations and quantum transport simulations, we demonstrate the existence of an acetylene-meditated transport mechanism entirely hosted by sp-hybridized orbitals. For that we propose a series of nanostructured 2D materials featuring linear arrangements of closely packed acetylene units which function as sp-nanowires. Because of the very distinct nature of this unique transport mechanism, it appears to be highly complementary with π-conjugation, thus potentially becoming a key tool for future carbon nanoelectronics.

Unveiling the Multiradical Character of the Biphenylene Network and Its Anisotropic Charge Transport

“…It has already been shown, via large-scale transport simulations, that structurally anisotropic carbon 2D materials lead to anisotropic electronic transport, such as in the case of nanoporous graphenes 50−52 or in the so-called grazynes. 10,11 A recent study of BPN has also predicted that phonons (i.e., thermal energy) are transported differently along the two in-plane directions. 26 However, till date, the electronic transport characteristics of this novel 2D material remain to be investigated.…”

“…Finally, quantum transport simulations demonstrate the anisotropic character of electronic transport in BPN. The spatial spreading of injected currents follows a Talbot interference pattern, which is a key feature of carbon 2D materials behaving as arrays of weakly coupled 1D nanoelectronic channels. , Additionally, this feature appears for both the non-spin-polarized metallic and multiradical states of BPN, suggesting that transport anisotropy is intrinsically linked to the structural in-plane anisotropy of the 2D material. Due to the spin-polarized character of the multiradical configuration, we find a strong spin-filtering effect of injected currents, which could potentially serve for spintronic applications …”

“…Graphene, the two-dimensional (2D) form of sp 2 carbon, 1 has catalyzed a pursuit for other 2D carbon allotropes, such as phagraphene, 2,3 graphane, 4 graphynes, 5−7 graphdyines, 8,9 grazynes, 10,11 and 2D π-conjugated polymers. 12−16 Interestingly, some of these materials have been experimentally synthesized, confirming, in particular cases, previously predicted electronic features such as semiconductor behavior or antiferromagnetism.…”

“…Graphene, the two-dimensional (2D) form of sp 2 carbon, has catalyzed a pursuit for other 2D carbon allotropes, such as phagraphene, , graphane, graphynes, − graphdyines, , grazynes, , and 2D π-conjugated polymers. − Interestingly, some of these materials have been experimentally synthesized, confirming, in particular cases, previously predicted electronic features such as semiconductor behavior or antiferromagnetism. ,− The biphenylene network (BPN) is the latest member of the 2D carbon allotrope family to be experimentally reported . As depicted in Figure a, it is made of a combination of 4-, 6-, and 8-membered rings.…”

Thermodynamic, kinetic and dynamic aspects of biogas upgrading using nano-engineered grazynes

“…Such structures have been proposed to display a peculiar new type of electronic current transportation across acetylenic neighbours. 13 Moreover, grazynes structure can be modified in different ways, either widening the width of the graphene stripes, enlarging the acetylenic bonds, or creating vacancies in such bonds. This high tunability allows the size of the pores present in the structure to be modified at will and profited in turn to maximize the chemical resolution of gases; this is, finding pore sizes that allow some molecules to pass across the membrane while others do not, and, by that, controlling the diffusion selectivity.…”