Photoluminescent Ti3C2 MXene Quantum Dots for Multicolor Cellular Imaging

The preparation of water-soluble, monolayered Ti3C2MQDs (MXene QDs) through a facile hydrothermal method was reported. Ti3C2MXene was obtained by selectively etching the A layer in the Ti3 AlC2 MAX phase with 48% HF acid. The MQDs were prepared through a facile hydrothermal method by cutting the bulk layered Ti3C2MXene. Colloidal MQDs with different morphologies could be obtained by changing the reaction temperature. The morphology and structure of the as-synthesized MQDs were studied using transmission electron microscopy (TEM) and atomic force microscopy (AFM). By adjusting the reaction temperatures, MQDs with different atomic concentrations of Ti were obtained. Detailed analysis indicate that the MQDs obtained at 100 °C adopt the pristine structure of MXene, and the MQDs obtained at 120 °C adopt a hybrid structure with C-Ti in the core and TiO2 at the surface. When the reaction temperature was increased to 150 °C, amorphous carbon dots were obtained.