A novel two-dimensional carbon allotrope with tunable bandgap

Carbon allotropes hold significant potential in diverse applications such as catalysis, energy storage, and semiconductor devices due to their flexibility in atomic/electronic configurations. In recent years, exploring novel carbon materials with unique electronic and optical properties has become a research hotspot. In this study, we reported a new two-dimensional carbon allotrope, 2D-TCH, synthesized via nanocluster assembly of Truncated Cuboctahedron (TCH) units. The material exhibits an orthorhombic lattice (Pnma symmetry) with hybrid $sp^{2}/sp^{3}$ bonding, and its dynamics, mechanical and thermodynamics stability is confirmed by phonon dispersion, Born-Huang criteria and molecular dynamics simulationsis. Using first-principles calculations, we investigated its electronic and optical properties, revealing a tunable bandgap. It is noteworthy that both electric fields and mechanical stress can exert influence on the electronic band structure of 2D-TCH, consequently modulating its optical properties. Our work demonstrates the potential of nanocluster-based assembly strategies for designing functional 2D carbon materials, offering applications in flexible electronics, strain sensors, and energy-efficient devices.