Chaos Phase Induced Mass-producible Monolayer Two-dimensional Material

TL;DR

This paper introduces a novel 2D MOF with a chaos phase, enabling mass production of monolayer nanosheets with high uniformity, large size, and wafer-scale film formation, bridging crystal and amorphous states.

Contribution

It reports the first mass-producible monolayer 2D material exhibiting a chaos phase, with unique structural and mechanical properties, expanding the understanding of amorphous-like 2D phases.

Findings

Achieved gram-scale exfoliation into monolayer nanosheets

Produced lateral sizes exceeding 10 micrometers

Formed wafer-scale films on substrates

Abstract

Crystal phase is well studied and presents a periodical atom arrangement in three dimensions lattice, but the "amorphous phase" is poorly understood. Here, by starting from cage-like bicyclocalix[2]arene[2]triazines building block, a brand-new 2D MOF is constructed with extremely weak interlaminar interaction existing between two adjacent 2D-crystal layer. Inter-layer slip happens under external disturbance and leads to the loss of periodicity at one dimension in the crystal lattice, resulting in an interim phase between the crystal and amorphous phase - the chaos phase, non-periodical in microscopic scale but orderly in mesoscopic scale. This chaos phase 2D MOF is a disordered self-assembly of black-phosphorus like 3D-layer, which has excellent mechanical-strength and a thickness of 1.15 nm. The bulky 2D-MOF material is readily to be exfoliated into monolayer nanosheets in gram-scale with unprecedented evenness and homogeneity, as well as previously unattained lateral size (>10 um), which present the first mass-producible monolayer 2D material and can form wafer-scale film on substrate.