No abstract

In this study, top-down syntheses of carbon dots (CDs) from four different carbon precursors, namely, carbon nano powders, graphite, graphene, and carbon nanotubes, were carried out. Systematic study demonstrated that the optical properties and surface functionalities of the CDs were quite similar and mainly influenced by the synthesis method, while the sizes, morphologies, chemical compositions, and core structures of the CDs were heavily influenced by the carbon precursors. On the basis of these studies, the formation processes and structural models of these four top-down CDs were proposed. The cell cytotoxicity and photothermal conversion efficiency of these CDs were also carefully evaluated, demonstrating their potential applications in photothermal therapy.

No abstract

The preparation of multicolor and white light-emitting carbon dots (CDs) is of both significant importance and challenging for their applications as white phosphors for light-emitting diodes (LEDs). In this report, a facile reaction system that is capable of preparing both multicolor and white light-emitting CDs was disclosed. In this system, three CDs emitting yellow, red, and green lights were prepared, and monochromatic LEDs were constructed using these multicolor CDs. Most importantly, single-component white light-emitting CDs with CIE coordinates of (0.33, 0.33) were also prepared. The white light-emitting CDs were applied as single-component white phosphors for the fabrication of white LEDs. The white LEDs constructed demonstrated excellent performance, emitting warm white light (CCT = 3723 K) with CIE coordinates of (0.39, 0.37) and an extremely high color-rendering index of 91.5, which should find favorable applications for indoor illumination.

No abstract