  The rich electronic and band structures of monolayered crystals distinguished
from their layered bulk counterparts offer versatile physical/chemical
properties and applications.1-5 Their fabrications, particularly the top-down
"exfoliations", are successful promised by the weak Van der Waals force between
monolayers.6-9 Differentially, un-zipping ultra-thin crystals (e.g. with only
one layer of crystal plane) from non-layered structures is highly challenging
due to the strong chemical bond between planes and atoms. Alterative finely
controlled growth of these ultra-thin materials is not really successful. This
work demonstrates how a technique can be used to unzip and disintegrate
ultra-thin crystal plane (e.g. monolayered nanocrystals and nanosheets) from
bulk non-layered structures (ZnO, alpha/belta-MnO2, TiO2, alpha-TiB2), and
present how the basic optical properties changed to distinguish from their bulk
phases. The work here gives a strong tool kit to various novel 2D non-layered
nanomaterials, providing significant contributions to the family of
two-dimensional materials, potentially paving the way for various practical
applications.
