As a recently created inorganic nanosheet
material, MXene has received
growing attention and has become a hotspot of intensive research.
The efficient morphology control of this class of material could bring
enormous possibilities for creating marvelous properties and functions;
however, this type of research is very scarce. In this work, we demonstrate
a general and mild approach for creating ultrasmall MXenes by simultaneous
intralayer cutting and interlayer delamination. Taking the most commonly
studied Ti<sub>3</sub>C<sub>2</sub> as an illustrative example, the
resulting product possessed monolayer thickness with a lateral dimension
of 2–8 nm and exhibited bright and tunable fluorescence. Further,
the method could also be employed to synthesize ultrasmall sheets
of other MXene phases, for example, Nb<sub>2</sub>C or Ti<sub>2</sub>C. Importantly, although the strong covalent M–C bond was
to some extent broken, all of the characterizations suggested that
the chemical structure was composed of well-maintained host layers
without observation of any serious damages, demonstrating the superior
reaction efficiencies and safeties of our methods. This work may provide
a facile and general approach to modulate various nanoscale materials
and could further stimulate the vast applications of MXene materials
in many optical-related fields
