Theoretical characterization of tolanene: A new 2D sp-sp2 hybridized carbon allotrope
Saif Ullah, Marcos G. Menezes, Alexander Silva
Abstract
The search for new carbon allotrope forms has been the focus of much experimental and theoretical research. Some nonbenzenoid sp 2 -hybridized carbon allotropes have been proposed and synthesized, revealing properties unlike those observed for graphene. In the present work, first-principles calculations were performed to investigate a new two-dimensional (2D) carbon sheet — named tolanene — which may hypothetically be obtained from diphenylacetylene molecules as building blocks. The nonbenzenoid tolanene sheet has a periodic arrangement of four-, six-, eight-, and twelve-membered rings of sp and sp 2 hybridized carbon atoms. Our calculations reveal that tolanene is mechanically and dynamically stable, and can potentially withstand a temperature as high as 1500 K quite easily. The structure presents a strong anisotropy in its mechanical properties, in a similar fashion to biphenylene . Additionally, we verify that the structure presents a metallic behavior, and its low-energy electronic structure is fully determined by p z orbitals, as in most carbon-based 2D materials . The application of tolanene as a potential anode material in Li-ion batteries is also explored. We find that it offers a competitive Li storage capacity and fast Li mobility along with other interesting electronic properties.