Two-Dimensional C60 Fullerene Networks (Graphullerene): Structure–Property Relations, Quantitative Benchmarking and Future Directions

Two-dimensional covalent C60 networks are molecularly derived carbon allotropes in which intact fullerene cages form the repeating units of an extended lattice. Since isolation of a monolayer network in 2022, the field has expanded from synthesis to fracture, transport, excitonics, tribology, membranes, catalysis and energy storage. Growth has outpaced comparability: nominally identical quantities can refer to different structures, methods or dimensional conventions. Using literature verified through to 9 September 2026, we review the field within an evidence-graded framework and restate recoverable mechanical results on a thickness-independent basis. For the quasi-hexagonal phase, moduli published in GPa span 49.6–218.5 GPa (~4.4-fold), whereas the recoverable/native set occupies 93–189 N m−1 (~2.0-fold). Because the populations are not identical, this is a benchmarking diagnostic rather than an effect size; the narrower recoverable range is consistent with thickness conventions contributing to the apparent scatter. Thermal transport remains less settled: the direct experimental benchmark (~2.7 W m−1 K−1) is for micrometre-thick layered material, while monolayer simulations span a few to >100 W m−1 K−1. Electronic studies establish a semiconducting, anisotropic platform, although reported gaps remain observable- and method-dependent. We conclude with reporting standards and research priorities for comparable C60-network studies.