Two-dimensional diamond
January2, 2026
Two-dimensional diamond
Diamane、Diamene、Diamondol、Diamondene、Diamanoid
Since the isolation of graphene in 2004, two-dimensional (2D) materials have become a central focus of condensed matter physics and materials science. Reducing materials to the atomic scale introduces pronounced quantum confinement, surface, and interface effects, often leading to physical properties that differ fundamentally from those of bulk solids. While graphene and other sp²-bonded 2D materials have been extensively explored, the realization of atomically thin sp³-bonded materials remains a major scientific challenge.
Diamond, composed of sp³-hybridized carbon atoms in a three-dimensional covalent network, exhibits an exceptional combination of properties, including an ultrawide bandgap, ultrahigh stiffness, outstanding thermal conductivity, chemical inertness, and extreme radiation tolerance. These attributes underpin its importance in high-power electronics, quantum technologies, and extreme-environment applications. Extending diamond to the two-dimensional limit is therefore of considerable interest. However, unlike layered materials held together by van der Waals forces, diamond lacks a natural cleavage plane, and its fully covalent structure makes direct exfoliation impossible. Moreover, nanoscale diamond structures are thermodynamically prone to graphitization, further complicating the stabilization of ultrathin diamond phases.
Recent advances have shown that sp²-bonded carbon frameworks can be transformed into sp³-bonded configurations under suitable external stimuli, including chemical functionalization, mechanical stress, and high pressure. Building on these insights, a family of atomically thin diamond-like carbon phases has been theoretically proposed and experimentally explored, beginning with the prediction of graphane and followed by structures such as diamane, diamene, and related derivatives. Collectively, these materials are referred to here as two-dimensional diamond (2D diamond).
Structurally, 2D diamond is typically formed by inducing interlayer covalent bonding in bilayer or few-layer graphene, accompanied by surface passivation with hydrogen, fluorine, or other functional groups, or by pressure-driven lattice reconstruction. First-principles calculations predict that these materials can adopt cubic- or hexagonal-diamond-like configurations with tunable electronic, mechanical, and thermal properties. Experimentally, evidence for 2D diamond formation has been obtained through chemical functionalization, substrate-assisted synthesis, and high-pressure techniques.
As the ultimate thickness limit of diamond-like materials, 2D diamond provides a unique platform for exploring stron
g covalent bonding, quantum confinement, and interfacial effects in two dimensions. Continued progress in synthesis and characterization is expected to unlock its potential for next-generation electronic, photonic, and quantum devices.
