Research / 2021 / Article / Fig 5

Review Article

Afterglow Carbon Dots: From Fundamentals to Applications

Figure 5

(a) Schematic representation of activation of the afterglow luminescence of CDs via MS encapsulation. In this strategy, a mixture of molten salts and CD precursors was heated at high temperatures for several to enable the carbonization of the precursors. When cooling to room temperature, molten salts were capped on the surface of the resulting CDs, allowing the formation of CDs@MS composites (adapted and copyright permission [80], Royal Society of Chemistry). (b) Photographs of CDs@MP dispersion under daylight, UV light (365 nm) on, and UV light off with different delay times, respectively. (c) Phosphorescence profile comparison of the CDs@MP in the solid and solution states. (d) The decay curve of the phosphorescence of the CDs@MP at 506 nm (adapted and copyright permission [52] (b–d), American Chemical Society). (e) Schematic representation of activation of the afterglow luminescence of CDs via host-guest encapsulation. In this strategy, CD precursors (guest molecules) were first inserted into the nanospace of layered compounds (host matrices) followed by heating treatment at high temperatures. In the heating treatment, the precursors were carbonized into CDs which are simultaneously encapsulated by the host inorganic matrices. (b) Photographs of CDs@LDHs under UV excitation and ceasing the excitation as a function of time. (c) The comparison of fluorescence and phosphorescence profiles of the resulting CDs@LDHs. (d) Phosphorescence decay behavior of the CDs@LDHs at 490 nm (adapted and copyright permission [81] (e–h), Royal Society of Chemistry).