Tailoring Graphite into Subnanometer Graphene

Abstract Within the intersection of materials science and nanoscience/technology, extremely downsized (including quantum‐sized and subnanometer‐sized) materials attract increasing interest. However, the effective and controllable production of extremely downsized materials through physical strategies remains a great challenge. Herein, an all‐physical top–down method for the production of sub‐1 nm graphene with completely broken lattice is reported. The graphene subnanometer materials (GSNs) with monolayer structures and lateral sizes of ≈0.5 nm are obtained. Compared with their bulk, nanosheets, and quantum sheets, the intrinsic GSNs present extremely enhanced photoluminescence and nonlinear saturation absorption performances, as well as unique carrier behavior. The non‐equilibrium states induced by the entirely exposed and broken, intrinsic lattices in sub‐1 nm graphene can be determinative to their extreme performances. This work shows the great potential of broken lattice and provides new insights toward subnanometer materials.