Versatile Cutting Method for Producing Fluorescent Ultrasmall MXene Sheets

Abstract

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 3 C 2 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 2 C or Ti 2 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.