Theoretical Investigation of the Electronic Properties of Graphyne Nanoribbons and Nanotubes Based on the Biphenylene Network

The search for novel carbon allotropes remains a central theme in both experimental and theoretical investigations. Following the synthesis of biphenylene (BPN) network, several proposals for two-dimensional graphyne-like nanostructures based on the BPN lattice have been explored. Recently, a graphyne-type BPN, known as α-BPNGY, has been shown to exhibit interesting properties, such as a spin-polarized semiconducting configuration. In this work, we use density functional theory to investigate the electronic properties that emerge from quantum confinement when the α-BPNGY layer is modified into quasi-one-dimensional (1D) structures. We show that the electronic behavior of nanotube-like systems depends on both chirality and diameter, while the nanoribbon-like structures are usually semiconductors with band gaps in the 0.07–0.46 eV range. The nanoribbons studied here have fully hydrogen-passivated edges, with frontier states spread over the inner region of the structure. Most of these quasi-1D systems exhibit spin-polarized configurations, with spin densities resembling those of their 2D counterpart. These systems display tunable properties, making them promising candidates for nanoelectronic applications.