Metallic monolayer iodinene sheets

Two-dimensional (2D) Xenens with varying degrees of buckling and tunable electronic structures are promising platforms for fundamental research and practical applications. So far, great efforts have been devoted to synthesizing new Xenes to expand the 2D family, particularly 2D iodine (iodinene), which holds promise for topological electronics. However, the unique physicochemical characteristics of iodine—such as low sublimation temperatures, high electronegativity, and chemical instability—have posed challenges for its reliable synthesis. Herein, we developed a template-mediated epitaxial approach to synthesize monolayer iodinene, which adopts a silicene-like buckled structure, via a mild solution-phase method. Iodinene crystallized on 2D templates, revealing a commensurate superlattice, highlighting that weak interfacial interactions and charge transfer play a significant role in stabilizing the buckled iodinene. The monolayer iodinene, exhibiting anomalous electronic character and flat band as suggested by the theoretical calculations, expands the family of 2D metallic Xenes and paves the way for researching non-trivial states in metastable monolayer Xenes.