White Photoluminescent Ti₃C₂ MXene Quantum Dots with Two-Photon Fluorescence

A recently created class of inorganic 2D materials, MXenes, has become a subject of intensive research. Reducing their dimensionality from 2D to 0D quantum dots (QDs) could result in extremely useful properties and functions. However, this type of research is scarce, and the reported Ti₃C₂ MXene QDs (MQDs) have only shown blue fluorescence emission. This work demonstrates a facile, high-output method for preparing bright white emitting Ti₃C₂ MQDs. The resulting product is two layers thick with a lateral dimension of 13.1 nm. Importantly, the as prepared Ti₃C₂ MQDs present strong two-photon white fluorescence. Their fluorescence under high pressure is also investigated and it is found that the white emission is very stable and the pressure makes it possible to change from cool white emission to warm white emission. Hybrid nanocomposites are then fabricated by polymerizing Ti₃C₂ MQDs in polydimethylsiloxane (PDMS) solution, and the bright white emitting hybrid materials in white light-emitting diodes are used. This work provides a facile and general approach to modulate various nanoscale MXene materials, and could further aid the wide development of applications for MXene materials in various optical-related fields.