The intrinsic thermal transport properties of the biphenylene network and the influence of hydrogenation: a first-principles study

Abstract

Utilizing first-principles calculations combined with phonon Boltzmann transport theory up to fourth-order anharmonicity, we systematically investigate the thermal transport properties of the biphenylene network [BPN, recently synthesized experimentally by Fan et al., Science, 2021, 372, 852–856] and hydrogenated BPN (HBPN). The calculations show that four-phonon scattering significantly affects the lattice thermal conductivity (κ) of BPN. At room temperature, the κ of BPN is reduced from 582.32 (1257.07) W m⁻¹ K⁻¹ to 309.56 (539.88) W m⁻¹ K⁻¹ along the x (y) direction after considering the four-phonon scattering. Moreover, our results demonstrate that the thermal transport in BPN could also be greatly suppressed by hydrogenation, where the κ of HBPN along the x (y) direction is merely 16.62% (10.14%) of that of pristine BPN at 300 K. The mechanism causing such an obvious decrease of κ of HBPN is identified to be due to the enhanced phonon scattering rate and reduced group velocity, which is further revealed by the increased scattering phase space and weakened C–C bond. The results presented in this work shed light on the intrinsic thermal transport features of BPN and HBPN, which will help us to understand the phonon transport processes and pave the way for their future developments in the thermal field.