De Novo Synthesis of Free-Standing Flexible 2D Intercalated Nanofilm Uniform over Tens of cm2.

Of a variety of intercalated materials, 2D intercalated systems have attracted much attention both as materials per se, and as a platform to study atoms and molecules confined among nanometric layers. High-precision fabrication of such structures has, however, been a difficult task using the conventional top-down and bottom-up approaches. The de novo synthesis of a 3-nm-thick nanofilm intercalating a hydrogen-bonded network between two layers of fullerene molecules is reported here. The two-layered film can be further laminated into a multiply film either in situ or by sequential lamination. The 3 nm film forms uniformly over an area of several tens of cm2 at an air/water interface and can be transferred to either flat or perforated substrates. A free-standing film in air prepared by transfer to a gold comb electrode shows proton conductivity up to 1.4 × 10-4 S cm-1 . Electron-dose-dependent reversible bending of a free-standing 6-nm-thick nanofilm hung in a vacuum is observed under electron beam irradiation.