One-pot green synthesis of oxygen-rich nitrogen-doped graphene quantum dots and their potential application in pH-sensitive photoluminescence and detection of mercury(II) ions

Shi, Bingfang; Zhang, Liangliang; Lan, Chuanqing; Zhao, Jingjin; Su, Yubin; Zhao, Shulin

doi:10.1016/j.talanta.2015.04.059

Cited by 158 publications

(57 citation statements)

References 53 publications

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“…We anticipate that this understanding will importantly advance the research on GQD-based sensing devices. The choice of GQDs as a representative of the graphene-family materials is justified by the fact that GQD-related systems are multifunctional platforms, which can be used for production of micron-sized solid sheets (a promising working electrode material for electrochemical detection of heavy metals), 68 catalysts accelerating the reaction with HMs, 69 modified working electrodes, 70,71 aqueous solution electrolytes for optical and colorimetric detection of heavy metals [72][73][74][75][76][77][78][79][80][81][82] and adsorbent agents for removal of heavy metals. [83][84][85]…”

Section: Introductionmentioning

confidence: 99%

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Shtepliuk

Yakimova

2018

Phys. Chem. Chem. Phys.

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High-performance optical detection of toxic heavy metals by using graphene quantum dots (GQDs) requires a strong interaction between the metals and GQDs, which can be reached through a functionalization/immobilization procedure or doping effect. However, commonly used surface activation approaches induce toxicity into the analysis system and, therefore, are ineligible from the environmental point of view. Here, we show that artificial creation of vacancy-type defects in GQDs can be a helpful means of intentional control of the active sites available for reaction with cadmium (Cd), mercury (Hg) and lead (Pb). Using restricted density functional theory (DFT) and time-dependent DFT (TD-DFT) methods, we predict the effect of vacancy complexes not previously studied to describe the binding ability of GQDs towards metal adsorbates. We also show that the interband absorption in closed-shell GQDs complexed with Cd, Hg and Pb is strongly dependent on the vacancy type and can be efficiently tuned to attain the desired coloration of the analysis system. The results suggest that the vacancy defects play an important role in governing the hybridization between locally-excited (LE) and charge-transfer (CT) states of the GQDs. Based on the molecular orbital analysis and in-depth knowledge of excited states, the mechanisms underlying the interband absorption are discussed.

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Section: Introductionmentioning

confidence: 99%

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Shtepliuk

Yakimova

2018

Phys. Chem. Chem. Phys.

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“…For example, NGQDs have been synthesized using glycine [21], glucose [14], or citric acid [22][23][24][25][26][27] as carbon source or using ammonia [14,22,23], dicyandiamide [24,25], tris(hydroxymethyl) aminomethane [26], 3,4-dihydroxy-L-phenylalanine [27], or glycine [21] as nitrogen source through hydrothermal reaction [14,[21][22][23][24][25] or high-temperature treatment [26,27]. Such one-step methods usually require high temperature and/ or high pressure.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast ammonia-driven, microwave-assisted synthesis of nitrogen-doped graphene quantum dots and their optical properties

et al. 2016

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Abstract:For the first time, a facile, ultrafast, ammoniadriven microwave-assisted synthesis of high-quality nitrogen-doped graphene quantum dots (NGQDs) at room temperature and atmospheric pressure is presented. This one-step method is very cheap, environment friendly, and suitable for large-scale production. The as-synthesized NGQDs consisting of one to three graphene monolayers exhibit highly crystalline quality with an average size of 5.3 nm. A new fluorescence (FL) emission peak at 390 nm is observed, which might be attributed to the doped nitrogen atoms into the GQDs. An interesting red-shift is observed by comparing the FL excitation spectra to the UV-visible absorption spectra. Based on the optical properties, the detailed Jablonski diagram representing the energy level structure of NGQDs is derived.

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“…The emission spectra of fluorescent carbon quantum dots is usually affected by the CQDs size and surface states (Han et al 2015;Hu et al 2015), which demonstrated that N-GQDs in the composite paper had both uniform size and surface activity. Moreover, the PL intensity of N-GQDs/G/C at 345 nm was much higher than that of the N-GQDs solution in previous reports (Dey et al 2014;Shi et al 2015). There are several possible reasons for this result.…”

Section: Fig 2 Xrd Patterns Of (A) Graphite (B) Go (C) N-gqds/gramentioning

confidence: 56%

A One-step Hydrothermal Method of Nitrogen-doped Graphene Quantum Dots Decorated Graphene for Fabrication of Paper-based Fluorescent Composite

Bian¹,

He²,

Li³

2016

BioResources

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A facile approach for producing fluorescent composite paper containing nitrogen-doped graphene quantum dots (N-GQDs) and graphene on the surface of the modified fibers was implemented from the exfoliation of graphite oxide (GO) using a one-step hydrothermal method. The properties of the composite paper were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV), photoluminescence spectroscopy (PL), and confocal laser scanning microscopy (CLSM). The results indicated that the GO was reduced to graphene sheets, and the N-GQDs nanoparticles were deposited on the surface of these sheets. The composite paper remained undamaged, with a three-dimensional structure and smooth fibers during the hydrothermal process, and the average particle size of N-GQDs was less than 10 nm. Photoluminescence measurements showed that the composite paper had a strong ultraviolet absorption in the range of 200 to 340 nm, and the band edge emission occurred at 475 nm. The CLSM image of composite paper exhibited a well-defined excitonic emission feature with an excitation wavelength of 405 nm.

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One-pot green synthesis of oxygen-rich nitrogen-doped graphene quantum dots and their potential application in pH-sensitive photoluminescence and detection of mercury(II) ions

Cited by 158 publications

References 53 publications

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Ultrafast ammonia-driven, microwave-assisted synthesis of nitrogen-doped graphene quantum dots and their optical properties

A One-step Hydrothermal Method of Nitrogen-doped Graphene Quantum Dots Decorated Graphene for Fabrication of Paper-based Fluorescent Composite

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