Atomic Scale Tracking of Single Layer Oxide Formation: Self-Peeling and Phase Transition in Solution

Liquid phase electron microscopy (TEM) is used to track the formation of In₂ O₃ ultrathin nanosheet in solution at atomic scale. This observation reveals that the formation of few atomic layer nanosheet goes through a complicated phase transition process from InCl₃ ^. 3H₂ O to In(OH)₃ and then to In₂ O₃ . Interestingly, the intermediate InCl₃ ^. 3H₂ O nanosheet can grow via either layer by layer or the strain-driven enation growth from precursor solution. Moreover, in situ TEM results and density functional theory (DFT) calculations demonstrate that the oleylamine is responsible for the self-peeling process. These findings can provide atomic-level insight for the understanding of how 2D nanomaterial grows and transforms in solution.