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Controllable size-selective method to prepare graphene quantum dots from graphene oxide.

Fan T, Zeng W, Tang W, Yuan C, Tong S, Cai K, Liu Y, Huang W, Min Y, Epstein AJ - Nanoscale Res Lett (2015)

Bottom Line: We demonstrated one-step method to fabricate two different sizes of graphene quantum dots (GQDs) through chemical cutting from graphene oxide (GO), which had many advantages in terms of simple process, low cost, and large scale in manufacturing with higher production yield comparing to the reported methods.Bright blue luminescent GQDs were obtained with a produced yield as high as 34.8%.Moreover, how the different sizes affect fluorescence wavelength mechanism was investigated in details.

View Article: PubMed Central - PubMed

Affiliation: Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, Jiangsu 210046 China.

ABSTRACT
We demonstrated one-step method to fabricate two different sizes of graphene quantum dots (GQDs) through chemical cutting from graphene oxide (GO), which had many advantages in terms of simple process, low cost, and large scale in manufacturing with higher production yield comparing to the reported methods. Several analytical methods were employed to characterize the composition and morphology of the resultants. Bright blue luminescent GQDs were obtained with a produced yield as high as 34.8%. Moreover, how the different sizes affect fluorescence wavelength mechanism was investigated in details.

No MeSH data available.


TEM and AFM characterization. (a) TEM images of GQDs-1 at 20 nm. (b) The HRTEM images of GQDs-1 with measured lattice spacing and edge structures at 2 nm. (c) Diameter distribution of the GQDs-1. (d) TEM images of GQDs-2 at 20 nm. (e) The HRTEM images of GQDs-2 with measured lattice spacing and edge structures at 2 nm. (f) Diameter distribution of the GQDs-2.
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Fig3: TEM and AFM characterization. (a) TEM images of GQDs-1 at 20 nm. (b) The HRTEM images of GQDs-1 with measured lattice spacing and edge structures at 2 nm. (c) Diameter distribution of the GQDs-1. (d) TEM images of GQDs-2 at 20 nm. (e) The HRTEM images of GQDs-2 with measured lattice spacing and edge structures at 2 nm. (f) Diameter distribution of the GQDs-2.

Mentions: TEM showed that the collected GQDs-1 was monodisperse and had a uniform diameter of 2–4 nm in size, and GQDs-2 was disperse and had a diameter of 3–5 nm (Figure 3a, d), which was much smaller than those of GQDs (around 10 nm) were synthesized by cutting GO sheets with modified Hummers oxidation cutting methods. In HRTEM images of GQDs-1 with measured lattice spacing, it was shown that GQDs-1 has lattice spacing of 0.23 nm and GQDs-2 has lattice spacing of 0.24 nm as shown in Figure 3b, e. The detailed analysis of HRTEM images for GQDs-1 showed that the periphery of GQDs-1 and GQDs-2 consisted of mixed zigzag and armchair edges. We find that both edges were mixed in curved periphery while the armchair edge appears more frequently in straight periphery. As a consequence, it appeared that armchair edges GQDs-1 consist of both edges and GQDs-2 consist mostly of curved periphery.Figure 3


Controllable size-selective method to prepare graphene quantum dots from graphene oxide.

Fan T, Zeng W, Tang W, Yuan C, Tong S, Cai K, Liu Y, Huang W, Min Y, Epstein AJ - Nanoscale Res Lett (2015)

TEM and AFM characterization. (a) TEM images of GQDs-1 at 20 nm. (b) The HRTEM images of GQDs-1 with measured lattice spacing and edge structures at 2 nm. (c) Diameter distribution of the GQDs-1. (d) TEM images of GQDs-2 at 20 nm. (e) The HRTEM images of GQDs-2 with measured lattice spacing and edge structures at 2 nm. (f) Diameter distribution of the GQDs-2.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4385023&req=5

Fig3: TEM and AFM characterization. (a) TEM images of GQDs-1 at 20 nm. (b) The HRTEM images of GQDs-1 with measured lattice spacing and edge structures at 2 nm. (c) Diameter distribution of the GQDs-1. (d) TEM images of GQDs-2 at 20 nm. (e) The HRTEM images of GQDs-2 with measured lattice spacing and edge structures at 2 nm. (f) Diameter distribution of the GQDs-2.
Mentions: TEM showed that the collected GQDs-1 was monodisperse and had a uniform diameter of 2–4 nm in size, and GQDs-2 was disperse and had a diameter of 3–5 nm (Figure 3a, d), which was much smaller than those of GQDs (around 10 nm) were synthesized by cutting GO sheets with modified Hummers oxidation cutting methods. In HRTEM images of GQDs-1 with measured lattice spacing, it was shown that GQDs-1 has lattice spacing of 0.23 nm and GQDs-2 has lattice spacing of 0.24 nm as shown in Figure 3b, e. The detailed analysis of HRTEM images for GQDs-1 showed that the periphery of GQDs-1 and GQDs-2 consisted of mixed zigzag and armchair edges. We find that both edges were mixed in curved periphery while the armchair edge appears more frequently in straight periphery. As a consequence, it appeared that armchair edges GQDs-1 consist of both edges and GQDs-2 consist mostly of curved periphery.Figure 3

Bottom Line: We demonstrated one-step method to fabricate two different sizes of graphene quantum dots (GQDs) through chemical cutting from graphene oxide (GO), which had many advantages in terms of simple process, low cost, and large scale in manufacturing with higher production yield comparing to the reported methods.Bright blue luminescent GQDs were obtained with a produced yield as high as 34.8%.Moreover, how the different sizes affect fluorescence wavelength mechanism was investigated in details.

View Article: PubMed Central - PubMed

Affiliation: Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, Jiangsu 210046 China.

ABSTRACT
We demonstrated one-step method to fabricate two different sizes of graphene quantum dots (GQDs) through chemical cutting from graphene oxide (GO), which had many advantages in terms of simple process, low cost, and large scale in manufacturing with higher production yield comparing to the reported methods. Several analytical methods were employed to characterize the composition and morphology of the resultants. Bright blue luminescent GQDs were obtained with a produced yield as high as 34.8%. Moreover, how the different sizes affect fluorescence wavelength mechanism was investigated in details.

No MeSH data available.