A prediction of a new porous metallic carbon allotrope with an sp2 hybridized network: cP-C24

Abstract

A new porous carbon allotrope, having 24 carbon atoms per cubic cell with a symmetry of P4132 (named as cP-C24), is theoretically predicted by first-principle calculations. Its dynamical, mechanical and thermal stabilities have been determined by phonon, elastic constants and ab initio molecular dynamics (AIMD). The mass density (2.26 g/cm3) is close to that of graphite (2.24 g/cm3). The energy of cP-C24 reveals that it is less stable than H18 carbon, diamond and graphite, but it is more stable than K6 carbon and T carbon. Furthermore, the AIMD simulations demonstrate that cP-C24 is not only thermally stable at 300 K but also at 1500 K. No band gap in the band structures demonstrates that it is metallic. Additionally, the calculated X-ray diffraction of cP-C24 has three peaks matched with the ones in previous detonated samples, indicating that the presence of cP-c24 may be produced by the detonation. Due to its porous structure, metallic property and high-temperature thermal stability, cP-C24 has potential applications for adsorption small molecules and atoms, electrode and high-temperature resistance.