Room temperature and solvothermal green synthesis of self passivated carbon quantum dots

Adsorptive desulfurization using different passivated carbon nanoparticles by PEG-200

“…The peaks around 3400, 1700, and 1100 cm −1 respectively correspond to the vibrations of C\OH, C_O, and C\O bonds, and the peaks at about 3000 and 1500 cm −1 are due to the C\H stretch of polycyclic aromatic hydrocarbons [28]. In addition a characteristic peak appeared around 1400 cm −1 which clarified the O\H bending [30]. FTIR analysis showed that the surfaces of the CNPs were significantly covered with hydrophilic groups (\OH and \COOH) which are produced from the decomposition of PEG at elevated temperature and are covalently bonded to the carbon frameworks, improving the hydrophilicity and stability of the nanoparticles in aqueous systems [27].…”

“…Polymers, such as diamine-terminated oligomeric poly-(ethylene glycol) (PEG1500N) and poly (propionylethyleneimine-coethyleneimine) (PPEI-EI), have been widely used as passivating agent [31,32]. Recently the nontoxic polymer PEG-200 has been used with dual purpose, both as the source of CNPs and afterward as a passivating agent (self-passivated CNPs) [30,33]. Our results in separation media showed that only passivated CNPs are capable of the uptake of sulfur from organic phase.…”

“…Surface passivation is the most promising technique for enhancing the photoluminescence (PL) properties of CNPs. After passivation the CNPs exhibit minimum toxicity, so they are used as a bioimaging agent against human red blood cells (RBCs) and the human liver carcinoma Hep G2 cell line [30]. Polymers, such as diamine-terminated oligomeric poly-(ethylene glycol) (PEG1500N) and poly (propionylethyleneimine-coethyleneimine) (PPEI-EI), have been widely used as passivating agent [31,32].…”

Green synthesis of luminescent carbon dots and carbon-coated metal particles: Two birds with one stone

“…Besides, the QY of the present synthesized carbon dots is also higher than some of the previous reported carbon dots. For example, the present QY is higher than the carbon dots synthesized with saccharide and base (1.2%) [24], higher than the carbon dots synthesized from natural gas soot (0.43%) [25] and higher than carbon dots synthesized from PEG (1.95%) [26]. Until now, the exact mechanism of the unique fluorescence property of carbon dots has not yet been clearly reported.…”

Perylenetetracarboxylic anhydride as a precursor of fluorescent carbon nanoonion rings

“…[2][3][4][5][6] Thermolysis of polyethylene glycol (PEG) at temperature of 400 ºC has been reported to be sufficient to generate C-dots. [7][8][9][10] In other reports, PEG is used as additive in the preparation of fluorescent Cdots to cover and protect their surface, resulting in an increase of the emission intensity. [11][12][13] Studies describing aromatic compounds as precursors of C-dots are much scarcer.…”