Intrinsic toughening in monolayer amorphous carbon nanocomposites

Two-dimensional (2D) materials have immense potential to advance flexible electronics, yet they are limited by low fracture toughness. This study addresses the intrinsic toughening of monolayer amorphous carbon (MAC), a 2D nanocomposite, to overcome this challenge. By incorporating both amorphous and nanocrystalline phases, MAC significantly enhances energy absorption during fracture propagation, as evidenced by crack blunting, deflecting, and bridging. Using in situ tensile tests under a scanning electron microscope, our results indicate an 8-fold increase in the energy release rate compared to monolayer graphene, along with improved fracture strain and crack stability. Molecular dynamics simulations demonstrate the impact of phase composition on fracture energy. Our results present a scalable toughening strategy for 2D materials, potentially broadening their applications in fields requiring robust fracture resistance.