Facile Exfoliation of Two-Dimensional Crystalline Monolayer Nanosheets from an Amorphous Metal–Organic Framework

Abstract

The large-scale preparation of monolayer two-dimensional (2D) material remains a great challenge, which hinders its real-world applications. Herein, we report a novel layered metal–organic framework (MOF), IPM-1, which was synthesized from a cage-like organic linker, with extremely weak interlaminar interaction. When subjected to external disturbance, IPM-1 degenerated into an intermediate state between the crystalline and amorphous phase, in which the layers retain the in-plane two-dimensional periodic structure but are misaligned in the third dimension, leading to the loss of apparent porosity and crystallinity. This amorphous IPM-1 is readily exfoliated at gram scale into crystalline 2D nanosheets with a thickness of 1.15 nm, excellent thickness homogeneity, lateral size up to 10 μm, and restored microporosity. IPM-1 nanosheets exhibit high chemical stability and catalytic activity in the oxidation of alcohol, combining the advantages of both.