N, B-Codoping Induces High-Efficiency Solid-State Fluorescence and Dual Emission of Yellow/Orange Carbon Dots

Abstract

Carbon dots (CDs) have attracted a lot of attention because of their tunable emission wavelength, high photobleaching resistance, and environmental friendliness. However, they suffer from aggregation-induced quenching in the solid state, which limits their application in solid-state fields. In this work, yellow-and orange-emissive N, B-codoped CDs (y-NB-CDs and o-NB-CDs) with highly efficient solid-state fluorescence and dual emission were achieved by a facile one-step microwave method. The obtained y-NB-CDs in the powder state show bright yellow fluorescence with a high solid-state QY of 39.0% and typical dual emission peaks at 484 and 565 nm. The as-synthesized o-NB-CDs in the powder state exhibit bright orange fluorescence with a high solid-state QY of 31.1% and dual emission at 484 and 585 nm. After systematically studying the effect of N, B-codoping on the solid-state fluorescence of NB-CDs, we demonstrate that the hydrogen bond between B−OH on the surface of the NB-CDs can inhibit the direct contact of nanoparticles, and a high content of graphitic N in NB-CDs can increase the probability of the radiative process of the aromatic domains, both of which trigger high-efficiency solid-state fluorescence of NB-CDs. This finding provides a general and efficient method for highly emissive solid-state CDs. In addition, N, Bcodoping can also give NB-CDs dual emission in the short-wavelength and long-wavelength regions, ascribed to the carbon core and surface defect state, respectively. Finally, y-NB-CDs were demonstrated as a phosphor to prepare a near white light-emitting diode with a color rendering index of 84 by combining them with an ultraviolet chip.

Nanotube‐Boramidic Acid Derivative for Dopamine Sensing

“…The presence of two different peaks in the O1s region can be explained by C=O (532.4 eV), and O−B (532.5 eV). Lastly, the deconvolution of B1s spectra shows three broad peaks responsible for BO x N y (192.1 eV), B−N (193 eV), and B−O (194.2 eV) [26g–h] . This information confirmed the proper functionalization of MWCNTs with ethylenediamine and boric acid [26a–b] …”

“…Functionalization of MWCNTs with ethylenediamine and boric acid exhibited two new peaks, belonging to B1s and N1s at the binding energies of 192.1 and 401.1 eV, which did not exist MWCNTs‐Cl. The deconvolution of the C1s spectra shows the three fitted peaks located at about 284.1, 285.4, and 287.4 eV, assigned to the C=C, C−N, and O=C−NH, respectively [26c–j] . The high‐resolution N1s spectrums are fitted to four pronounced peaks located at 399, 401.1, 401.7, and 403.6 eV, which can be attributed to N−B, −CO−NH−, −CH 2 −NH 2 , and C−N, respectively [26c,g] …”

Facile Synthesis of Multi-Emission Nitrogen/Boron Co-Doped Carbon Dots from Lignin for Anti-Counterfeiting Printing

“…As seen in the FTIR spectra ( Figure 3 c), the broad peaks from 3000 to 3680 cm −1 represent O-H/N-H functional groups. The peaks located at 2934, 1734, 1597 and 1215 cm −1 are assigned to the saturated C-H, C=O, C=C and C-O/C-N stretching vibrations, respectively [ 12 ]. The peaks observed at 1368, 1115 and 1033 cm −1 reveal the presence of B-O/B-N, B-OH and C-B functional groups [ 27 , 28 ].…”

“…To address the above challenge, the multi-emission CD anti-counterfeiting materials have been developed for achieving multiple kinds of fluorescence in a single security label by changing stimuli factors, thus realizing advanced multi-level optical anti-counterfeiting [ 9 , 10 , 11 ]. Wang et al [ 12 ] prepared dual-emission CDs with yellow/orange fluorescence from phloroglucinol dihydrate, boric acid and ethylenediamine by a one-step microwave method, which exhibited a high solid-state fluorescence QY of 39.0%. Li et al [ 13 ] prepared dual-emission CDs through facile hydrothermal carbonization of alizarin carmine as the precursor, exhibiting attractive blue/red dual-emissive fluorescence at 430 and 642 nm.…”

Strategy to Synthesize Tunable Multiemission Carbon Dots and Their Multicolor Visualization Application

“…Previous studies have constructed many ratiometric fluorescent probes by coupling CDs and other fluorescent emitters, including small organic molecules, gold clusters, , and inorganic quantum dots, , with different emissions. In addition to covalently connecting two emitters, few studies have prepared dual-emission CDs that simultaneously perform two fluorescent peaks to design ratiometric probes, in lieu of two separate fluorescent emitters. − For instance, Shangguan et al synthesized dual-emission CDs, which show two peaks at 475 and 545 nm . They first used the novel dual-emission CDs for ratiometric FL pH sensing.…”