Thermal-Undoping-Induced 2D Sheet Exfoliations in 1D Nanomaterial

Exfoliations leading to monolayer sheets are mostly reported in 2D materials such as graphene, WS₂, MoS₂, etc. However, theoretically it is established that exfoliations can also be possible for 1D materials like Sb₂S₃, though this has not been experimentally reported yet. Furthermore, most of the reported exfoliations are carried out with physical processes, and only in few cases complicated chemical pathways are also established. Keeping a view on the importance of both materials and methods, herein the exfoliation of 1D Sb₂S₃ nanostructures was reported via a unique thermal undoping approach where annealing expelled Sn atoms from the crystal lattice of 1D Sn-doped Sb₂S₃ nanostructures, leading to 2D sheets via very intriguing 1D-2D coupled structures. Sb₂S₃ is a 1D material but associated with 2D van der Waals forces, and in our dopant removal approach, exfoliation was exclusively carried out in directions perpendicular to the major axis of doped nanostructures. Apart from experimental supports, DFT calculation was also carried out keeping Sn in substitutional and interstitial positions to support our claim. These results suggest that designing a proper chemical process could successfully exfoliate the 1D materials, and the same might be extended to other materials of the same family.