Synthesis Strategies, Optical Mechanisms, and Applications of Dual-Emissive Carbon Dots

Abstract

Tuning the optical properties of carbon dots (CDs) and figuring out the mechanisms underneath the emissive phenomena have been one of the most cutting-edge topics in the development of carbon-based nanomaterials. Dual-emissive CDs possess the intrinsic dual-emission character upon single-wavelength excitation, which significantly benefits their multi-purpose applications. Explosive exploitations of dual-emissive CDs have been reported during the past five years. Nevertheless, there is a lack of a systematic summary of the rising star nanomaterial. In this review, we summarize the synthesis strategies and optical mechanisms of the dual-emissive CDs. The applications in the areas of biosensing, bioimaging, as well as photoelectronic devices are also outlined. The last section presents the main challenges and perspectives in further promoting the development of dual-emissive CDs. By covering the most vital publications, we anticipate that the review is of referential significance for researchers in the synthesis, characterization, and application of dual-emissive CDs.

The Enhanced Photoluminescence Properties of Carbon Dots Derived from Glucose: The Effect of Natural Oxidation

“…There are lots investigations about the PL mechanisms of dual-fluorescent CDs; several excitation and recombination models have been proposed to explain the luminescence processes, including the size effect (usually referred to as the sp 2 nanodomain), surface states, molecule states, the synergistic effect, etc. [ 10 , 11 , 39 , 40 , 41 , 42 ]. A large number of results demonstrate that the emission states induced by the oxygen-containing groups play a significant role in the optical properties of CDs [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 39 , 40 , 41 , 42 ].…”

“…[ 10 , 11 , 39 , 40 , 41 , 42 ]. A large number of results demonstrate that the emission states induced by the oxygen-containing groups play a significant role in the optical properties of CDs [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 39 , 40 , 41 , 42 ]. However, these oxygenous functional groups have diverse structural compositions, including the hydroxyl (–OH), carbonyl (C=O), carboxyl (–COOH), and epoxy (C–O–C) groups.…”