Green-emitting carbon quantum dots (G-CQDs) were prepared using tartaric acid and bran by one-pot solvothermal treatment and had photoluminescence quantum yields (PL QY) as high as 46%.

In this study, by adjusting sulfuric acid concentrations, tunable multicolour S/N‐carbon quantum dots (CQDs) were synthesized from waste foam as the raw material. The S/N‐CQDs presented blue, blue–green, green, green–yellow and yellow emission with an emission peak shifting from 475 to 589 nm and with optimum excitation wavelengths of 385, 405, 440, 450, and 500 nm, respectively. Using transmission electron microscopy, the S/N‐CQDs were seen to be spherical in morphology with a size around 6–8 nm. Fourier transform infrared spectra and X‐ray photoelectron spectroscopy indicated that the surface of the S/N‐CQDs was highly oxidized and sulfur doped. The fluorescence mechanism of multicolour S/N‐CQDs emission was mainly related to a band gap change caused by the surface state. Blue‐emitting S/N‐CQDs were used as a fluorescent probe that was highly selective and sensitive to Cr3+ ions, with a low detection limit of 6 μM. The waste foam‐derived S/N‐CQDs exhibited promising potential for ion detection in real water samples due to its excellent fluorescence activity.

A series of new polyfluorenes with dendritic functional cabazole and oxazole side chains have been successfully designed, synthesized, and characterized. These copolymers show good thermal properties and solubility in organic solvents, such as THF, CH2Cl2, CHCl3, toluene, etc. The photoluminescent (PL) and electroluminescent (EL) emission color quality was improved very much due to less aggregates of main chains of polyfluorenes (PFs) with the steric hindrance of dendritic functional carbazole and oxazole units. The electroluminescent devices based on these copolymers as blue emitters and host materilas were fabricated and evaluated. Balanced carriers and high efficiencies were obtained in both nonphosphorescent and phosphorescent PLEDs. The best devices were obtained by using PFCO1 materilas with the exteral quantum efficiencies of 1.03% for ITO/PEDOT/PFCO1/TPBI/LiF/Al and 11.63% for ITO/PEDOT/PFCO1:(tpbi)2Ir(acac)/Ca/Al. The results indicated that these copolymers were promising candicates for both efficient pure blue emitters and host materials for highly efficient phosphorescent PLEDs.

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N,S co-doped carbon nanodots are prepared and utilized in a facile fluorescent cytosensor.