Synthesis and Photoluminescence Properties of MoS2/Graphene Hetero-Structure by Liquid Phase Exfoliation

Synthesis of MoS2/Graphene hetero-structure in single stage, liquid-phase exfoliation in 7:3 isopropyl alcohol /water mixture and its consequences on the photoluminescence behavior of MoS2 have been studied. Thus synthesized hetero-structure was characterized using UV-visible, micro-Raman spectroscopy, Transmission electron microscopy(TEM), and Dynamic Light Scattering (DLS) analysis. UV-Visible and micro-Raman analysis confirm improved exfoliation to the level of monolayer hetero-structure. The photophysical properties of the hetero-structure were analyzed using steady state and time resolved luminescence techniques. An enhanced photoluminescence observed in the case of hetero-structure probably due to increase in the defect sites or reduction in the rate of non-radiative decay upon formation of sandwiched hetero-structure. Applications of this hetero-structure for fluorescence live cell imaging carried out and the hetero-structure demonstrated a better luminescence contrast compared to its individual counterpart MoS2 in phosphate buffered saline (PBS).

Download Full-text

Liquid-Phase Exfoliation of Few-Layer Graphene and Effect of Sonication Time on Concentration of Produced Few Layer Graphene

Nano Hybrids and Composites ◽

10.4028/www.scientific.net/nhc.14.17 ◽

2017 ◽

Vol 14 ◽

pp. 17-24 ◽

Cited By ~ 6

Author(s):

Syed Sajid Ali Shah ◽

Habib Nasir

Keyword(s):

Liquid Phase ◽

Cost Effective ◽

Production Method ◽

Commercial Production ◽

Sonication Time ◽

High Concentration ◽

Layer Graphene ◽

Uv Visible ◽

Liquid Phase Exfoliation ◽

Few Layer Graphene

Although graphene has been produced by various methods at lab scale, however, its cost effective mass production method is still a challenge. Graphene has been produced by liquid phase exfoliation, which is the most probable method for commercial production of graphene for various industrial applications.This paper reports high concentration production of few-layer graphene in DMSO (dimethyl sulfoxide) as solvent through liquid phase exfoliation assisted with sonication. The temperature was kept below 30oC. SEM, AFM, and XRD were used to characterize the produced graphene. SEM results confirm the production of few-layer graphene. EDX analysis shows that the graphene surface is free from oxides and impurities. AFM results also confirm the production of few-layer graphene. The UV-visible spectrophotometer was used to determine the concentration of the produced graphene, and the investigations demonstrate that the graphene production was increased by increasing the sonication time. There exist a linear relationship between the amount of produced graphene and sonication time for supplying energy during sonication.

Download Full-text

Tunable UV-visible absorption of SnS2layered quantum dots produced by liquid phase exfoliation

Nanoscale ◽

10.1039/c6nr09022b ◽

2017 ◽

Vol 9 (5) ◽

pp. 1820-1826 ◽

Cited By ~ 25

Author(s):

Xiao Fu ◽

P. Ilanchezhiyan ◽

G. Mohan Kumar ◽

Hak Dong Cho ◽

Lei Zhang ◽

...

Keyword(s):

Quantum Dots ◽

Liquid Phase ◽

Visible Absorption ◽

Uv Visible ◽

Liquid Phase Exfoliation

Download Full-text

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

Advanced Functional Materials ◽

10.1002/adfm.202010401 ◽

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

Download Full-text

Green Solvents for the Liquid-Phase Exfoliation of Biochars

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.1c02823 ◽

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

Download Full-text

Influence of the composition of isopropyl alcohol/water mixture solvents in catalyst ink solutions on proton exchange membrane fuel cell performance

Journal of Power Sources ◽

10.1016/j.jpowsour.2012.10.055 ◽

2013 ◽

Vol 225 ◽

pp. 293-303 ◽

Cited By ~ 72

Author(s):

Trung Truc Ngo ◽

T. Leon Yu ◽

Hsiu-Li Lin

Keyword(s):

Fuel Cell ◽

Proton Exchange Membrane ◽

Isopropyl Alcohol ◽

Proton Exchange ◽

Cell Performance ◽

Water Mixture ◽

Fuel Cell Performance ◽

Alcohol Water ◽

Exchange Membrane

Download Full-text

Taming the excited state reactivity of imines – from non-radiative decay to aza Paternò–Büchi reaction

Chemical Society Reviews ◽

10.1039/d0cs00717j ◽

2021 ◽

Author(s):

Sunil Kumar Kandappa ◽

Lakshmy Kannadi Valloli ◽

Sapna Ahuja ◽

Jayachandran Parthiban ◽

J. Sivaguru

Keyword(s):

Excited State ◽

Radiative Decay ◽

Photophysical Properties

This review highlights the excited state characteristics of imines and processes that govern their photochemical and photophysical properties.

Download Full-text

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

Nanomaterials ◽

10.3390/nano11051072 ◽

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.

Download Full-text