Sn₃O₄ exfoliation process investigated by density functional theory and modern scotch-tape experiment

Van der Waals (vdW) layered materials have been receiving a great deal of attention, especially after the scotch-tape experiment using graphite and the unique properties of graphene. Sn₃O₄, which also presents a layered structure, has been widely employed in a variety of technologies, but without further understanding of its bulk properties. For the first time, a modern Scotch-tape nanomanipulation experiment carried on a Dual Beam Microscope is combined with Density Functional Theory to investigate the Sn₃O₄ bulk properties. Theoretically, we have shown that the interaction energy between Sn₃O₄ layers are in the same order of graphene layers (21 meV Å⁻²), indicating its vdW interaction nature, whereas for SnO is slightly stronger (26 meV Å⁻²). Then, the Dual Beam Microscope nanomanipulation of the Sn₃O₄ nanobelts revealed the weak layer-layer interactions along their stacking direction (plane (0 1 0)). Comparatively, when probing SnO and SnO₂ nanobelts, no exfoliation could be seen. The study of Sn₃O₄ electronic structure properties also presents the important role of the interfacial region to the valence and conduction band and, consequently, to the material band-gap. The outcome of this study will help improving some applications, e.g., knowing the total and local density of states can help understanding surface band bending following gases adsorption. To the best of our knowledge, this is the first study to show, combining experimental and theoretical techniques, Sn₃O₄ as a promising 2D material