  Recent experimental reports on the realizations of two-dimensional (2D)
networks of the C60-based fullerenes with anisotropic and nanoporous lattices
represent a significant advance, and create exciting prospects for the
development of a new class of nanomaterials. In this work, we employed
theoretical calculations to explore novel C60-based fullerene lattices and
subsequently evaluate their stability and key physical properties. After the
energy minimization of extensive structures, we could detect novel 2D, 1D and
porous carbon C60-based networks, with close energies to that of the isolated
C60 cage. Density functional theory results confirm that the C60-based networks
can exhibit remarkable thermal stability, and depending on their atomic
structure show metallic, semimetallic or semiconducting electronic nature.
Using the machine learning interatomic potentials, thermal and mechanical
responses of the predicted nanoporous 2D lattices were investigated. The
estimated thermal conductivity of the quasi-hexagonal-phase of C60 fullerene is
shown to be in an excellent agreement with the experimental measurements.
Despite of different atomic structures, the anisotropic room temperature
lattice thermal conductivity of the fullerene nanosheets are estimated to be in
the order of 10 W/mK. Unlike the majority of carbon-based 2D materials,
C60-based counterparts noticeably are predicted to show positive thermal
expansion coefficients. Porous carbon C60-based networks are found to exhibit
superior mechanical properties, with tensile strengths and elastic modulus
reaching extraordinary values of 50 and 300 GPa, respectively. The theoretical
results presented in this work provide a comprehensive vision on the
structural, energetic, electronic, thermal and mechanical properties of the
C60-based fullerene networks.
