School of Materials Science and Engineering, CAPT, BKL-MEMD, Peking University, Beijing 100871, China.
J Phys Chem Lett. 2023 Feb 2;14(4):1082-1087. doi: 10.1021/acs.jpclett.2c03305. Epub 2023 Jan 26.
Motivated by the unique geometries and novel properties of penta-graphene (PG) and its derivatives, we propose a new stable 3D carbon allotrope, penta-C72, which is composed of PG nanotubes by connecting adjacent tubes in a tip-to-tip manner. Using first-principles calculations, we confirm its dynamical, thermal, and mechanical stabilities and find that penta-C72 is semiconducting with an indirect bandgap of 2.12 eV. Its lattice thermal conductivities at 300 K are found to be anisotropic with values of 97.32 and 179.35 W/mK along the and directions, respectively, which are much lower than that of diamond (2664.93 W/mK) and carbon nanotube-based bct-C4 (1411.02 W/mK). A detailed analysis of both harmonic and anharmonic properties suggests that the soften acoustic phonon modes, the low Young's modulus, and strong anharmonicity are the key factors for the low lattice thermal conductivity. The study expands the family of carbon materials by assembling PG nanotubes.
受五边形石墨烯（PG）及其衍生物独特的几何形状和新颖性质的启发，我们提出了一种新的稳定的 3D 碳同素异形体五-C72，它由 PG 纳米管通过以尖端到尖端的方式连接相邻的纳米管构成。通过第一性原理计算，我们证实了它的动力学、热学和力学稳定性，并发现五-C72是间接带隙为 2.12eV 的半导体。在 300K 时，它的晶格热导率在 和 方向上分别为 97.32 和 179.35W/mK，各向异性，明显低于金刚石（2664.93W/mK）和基于碳纳米管的 bct-C4（1411.02W/mK）。对谐波和非谐性质的详细分析表明，软化的声学声子模式、低杨氏模量和强烈的非谐性是晶格热导率低的关键因素。该研究通过组装 PG 纳米管扩展了碳材料家族。
