scholarly journals Enhancing the Liquid-Phase Exfoliation of Graphene in Organic Solvents upon Addition of n-Octylbenzene

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Sébastien Haar ◽  
Mirella El Gemayel ◽  
Yuyoung Shin ◽  
Georgian Melinte ◽  
Marco A. Squillaci ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Organic Solvents ◽  
Liquid Phase Exfoliation

Liquid-phase exfoliation of graphene in organic solvents with addition of naphthalene

2014 ◽  
Vol 418 ◽  
pp. 37-42 ◽  
Author(s):  
Jiasheng Xu ◽  
Dinh Khoi Dang ◽  
Van Tam Tran ◽  
Xiaoyang Liu ◽  
Jin Suk Chung ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Organic Solvents ◽  
Liquid Phase Exfoliation

Liquid-Phase Exfoliation of Graphene in Organic Solvents with Addition of Picric Acid

2021 ◽  
Vol 33 ◽  
pp. 47-60
Author(s):  
Syed Sajid Ali Shah ◽  
Habib Nasir ◽  
Shehla Honey
Keyword(s):  
Liquid Phase ◽  
Organic Solvents ◽  
Picric Acid ◽  
Graphite Powder ◽  
Sem Analysis ◽  
Production Yield ◽  
Force Microscopy ◽  
One Step ◽  
Graphene Production ◽  
Liquid Phase Exfoliation

In this work, graphene was produced by liquid-phase exfoliation of graphite in different organic solvents with addition of picric acid. The graphene was easily produced by one step ultra-sonication of graphite powder in the organic solvents. The addition of picric acid has increased the graphene production yield in most of the solvents tested in this work. Picric acid serves as a “molecular wedge” to intercalate into the edge of graphite, which plays a key role during sonication and significantly improves the production yield of graphene. The products were analyzed by microscopic techniques, including atomic force microscopy (AFM) and scanning electron microscope (SEM). The AFM images indicate that the exfoliation efficiency and amount of graphene increased by addition of picric acid in organic solvents. Moreover, the AFM images also indicate presence of bilayer graphene. SEM analysis also shows that the addition of picric acid into the organic solvent favors the exfoliation process. The produced graphene was also analyzed by XRD, FTIR, Raman and UV-visible spectroscopy. The XRD results illustrate that exfoliation was best achieved in N-methyl-2-pyrrolidone (NMP) as a solvent. FTIR and Raman results indicate that addition of picric acid has slightly defected the produced graphene surface. The amount of graphene concentration was calculated by using Beer Lambert law, and it was observed that the graphene production yield was increased by using picric acid in most of the solvents. The maximum amount of graphene concentration (0.159 mg/ml) was achieved by adding 30 mg of picric acid in NMP.

An Unexpected Transformation of Organic Solvents into 2D Fluorescent Quantum Dots during Ultrasonication-Assisted Liquid-Phase Exfoliation

2019 ◽  
Vol 123 (41) ◽  
pp. 25412-25421 ◽  
Author(s):  
Saroj Kumar Das ◽  
Ramchandra Gawas ◽  
Satadru Chakrabarty ◽  
Gunda Harini ◽  
Rishabh Patidar ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Liquid Phase ◽  
Organic Solvents ◽  
Liquid Phase Exfoliation ◽  
Unexpected Transformation

PbSe Nanocrystals Produced by Facile Liquid Phase Exfoliation for Efficient UV–Vis Photodetectors

2021 ◽  
Vol 31 (17) ◽  
pp. 2010401
Author(s):  
Lingfeng Gao ◽  
Rui Wang ◽  
Artem V. Kuklin ◽  
Han Zhang ◽  
Hans Ågren
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Exfoliation

Green Solvents for the Liquid-Phase Exfoliation of Biochars

2021 ◽  
Author(s):  
Juliana L. Vidal ◽  
Stephanie M. V. Gallant ◽  
Evan P. Connors ◽  
Douglas D. Richards ◽  
Stephanie L. MacQuarrie ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Green Solvents ◽  
Liquid Phase Exfoliation

scholarly journals Impact of Pretreatment of the Bulk Starting Material on the Efficiency of Liquid Phase Exfoliation of WS2

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1072
Author(s):  
Steffen Ott ◽  
Melanie Lakmann ◽  
Claudia Backes
Keyword(s):  
Liquid Phase ◽  
Quantum Yield ◽  
Aspect Ratio ◽  
Optical Quality ◽  
Starting Material ◽  
Binding Strength ◽  
Photoluminescence Quantum Yield ◽  
Out Of Plane ◽  
Liquid Phase Exfoliation ◽  
Pretreatment Conditions

Liquid phase exfoliation (LPE) is widely used to produce colloidal dispersions of nanomaterials, in particular two-dimensional nanosheets. The degree of exfoliation, i.e., the length to thickness aspect ratio was shown to be intrinsically limited by the ratio of in-plane to out-of-plane binding strength. In this work, we investigate whether simple pretreatment of the starting material can be used to change the in-plane to out-of-plane binding strength through mild intercalation to improve the sample quality in sonication-assisted LPE. Five different pretreatment conditions of WS2 were tested and the dispersions size-selected through centrifugation. From optical spectroscopy (extinction, Raman, photoluminescence), information on nanosheet dimension (average lateral size, layer number, monolayer size) and optical quality (relative photoluminescence quantum yield) was extracted. We find that the pretreatment has a minor impact on the length/thickness aspect ratio, but that photoluminescence quantum yield can be increased in particular using mild sonication conditions. We attribute this to the successful exfoliation of nanosheets with a lower degree of basal plane defectiveness. This work emphasizes the complexity of the exfoliation process and suggests that the role of defects has to be considered for a comprehensive picture.

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