  Among exciting recent advances in the field of two-dimensional (2D)
materials, the successful fabrications of the C60 fullerene networks has been a
particularly inspiring accomplishment. Motivated by the recent achievements,
herein we explore the stability and physical properties of novel hexagonal
boron-carbon fullerene 2D heterostructures, on the basis of already synthesized
B40 and C36 fullerenes. By performing extensive structural minimizations of
diverse atomic configurations using the density functional theory method, for
the first time, we could successfully detect thermally and dynamically stable
boron-carbon fullerene 2D heterostructures. Density functional theory results
confirm that the herein predicted 2D networks exhibit very identical
semiconducting electronic natures with topological flat bands. Using the
machine learning interatomic potentials, we also investigated the mechanical
and thermal transport properties. Despite of different bonding architectures,
the room temperature lattice thermal conductivity of the predicted nanoporous
fullerene heterostructures was found to range between 4 to 10 W/mK.
Boron-carbon fullerene heterostructures are predicted to show anisotropic but
also remarkable mechanical properties, with tensile strengths and elastic
modulus over 8 and 70 GPa, respectively. This study introduces the possibility
of developing a novel class of 2D heterostructures based on the fullerene
cages, with attractive electronic, thermal and mechanical features.
