scholarly journals Synergistic Exfoliation of MoS2 by Ultrasound Sonication in a Supercritical Fluid Based Complex Solvent

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Xi Tan ◽  
Wenbin Kang ◽  
Jingfeng Liu ◽  
Chuhong Zhang

Abstract Molybdenum disulfide (MoS2) is an extremely intriguing low-D layered material due to its exotic electronic, optical, and mechanical properties, which could be well exploited for numerous applications to energy storage, sensing, and catalysis, etc., provided a sufficiently low number of layers is achieved. A facile exfoliation strategy that leads to the production of few-layered MoS2 is proposed wherein the exfoliation efficacy could be synergistically boosted to > 90% by exploiting ultrasound sonication in supercritical CO2 in conjunction with N-methyl-2-pyrrolidone (NMP) as the intercalating solvent, which is superior to general practiced liquid exfoliation methods wherein only the supernatant is collected to avoid the majority of unexfoliated sediments. The facile and fast exfoliation technique suggests an exciting and feasible solution for scalable production of few-layered MoS2 and establishes a platform that contributes to fulfilling the full potential of this versatile two-dimensional material.

2021 ◽  
Author(s):  
Tao Li ◽  
Xuefeng Chang ◽  
Lifang Mei ◽  
Xiayun Shu ◽  
Jidong Ma ◽  
...  

Ti3C2Tx is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti3C2Tx has problems such as collapse of the layered structure and low...


2021 ◽  
Vol 56 (12) ◽  
pp. 7451-7463
Author(s):  
Yusheng Wang ◽  
Xiaowei Wu ◽  
Nahong Song ◽  
Xiaohui Yang ◽  
Yafeng Zheng ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 120
Author(s):  
Qing Peng

Although meta-generalized-gradient approximations (meta-GGAs) are believed potentially the most accurate among the efficient first-principles calculations, the performance has not been accessed on the nonlinear mechanical properties of two-dimensional nanomaterials. Graphene, like two-dimensional silicon carbide g-SiC, has a wide direct band-gap with applications in high-power electronics and solar energy. Taken g-SiC as a paradigm, we have investigated the performance of meta-GGA functionals on the nonlinear mechanical properties under large strains, both compressive and tensile, along three deformation modes using Strongly Constrained and Appropriately Normed Semilocal Density Functional (SCAN) as an example. A close comparison suggests that the nonlinear mechanics predicted from SCAN are very similar to that of Perdew-Burke-Ernzerhof (PBE) formulated functional, a standard Density Functional Theory (DFT) functional. The improvement from SCAN calculation over PBE calculation is minor, despite the considerable increase of computing demand. This study could be helpful in selection of density functionals in simulations and modeling of mechanics of materials.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sahib Hasan ◽  
Khagendra Baral ◽  
Neng Li ◽  
Wai-Yim Ching

AbstractChalcogenide semiconductors and glasses have many applications in the civil and military fields, especially in relation to their electronic, optical and mechanical properties for energy conversion and in enviormental materials. However, they are much less systemically studied and their fundamental physical properties for a large class chalcogenide semiconductors are rather scattered and incomplete. Here, we present a detailed study using well defined first-principles calculations on the electronic structure, interatomic bonding, optical, and mechanical properties for 99 bulk chalcogenides including thirteen of these crytals which have never been calculated. Due to their unique composition and structures, these 99 bulk chalcogenides are divided into two main groups. The first group contains 54 quaternary crystals with the structure composition (A2BCQ4) (A = Ag, Cu; B = Zn, Cd, Hg, Mg, Sr, Ba; C = Si, Ge, Sn; Q = S, Se, Te), while the second group contains scattered ternary and quaternary chalcogenide crystals with a more diverse composition (AxByCzQn) (A = Ag, Cu, Ba, Cs, Li, Tl, K, Lu, Sr; B = Zn, Cd, Hg, Al, Ga, In, P, As, La, Lu, Pb, Cu, Ag; C = Si, Ge, Sn, As, Sb, Bi, Zr, Hf, Ga, In; Q = S, Se, Te; $$\hbox {x} = 1$$ x = 1 , 2, 3; $$\hbox {y} = 0$$ y = 0 , 1, 2, 5; $$\hbox {z} = 0$$ z = 0 , 1, 2 and $$\hbox {n} = 3$$ n = 3 , 4, 5, 6, 9). Moreover, the total bond order density (TBOD) is used as a single quantum mechanical metric to characterize the internal cohesion of these crystals enabling us to correlate them with the calculated properties, especially their mechanical properties. This work provides a very large database for bulk chalcogenides crucial for the future theoretical and experimental studies, opening opportunities for study the properties and potential application of a wide variety of chalcogenides.


2019 ◽  
Vol 1184 ◽  
pp. 443-451 ◽  
Author(s):  
Amanda M.L. Estolano ◽  
Nathan B. Lima ◽  
Rogerio V.A. Junior ◽  
Marcia K.D.L. Belarmino ◽  
Anderson I.S. Silva ◽  
...  

2013 ◽  
Vol 341 ◽  
pp. 169-180 ◽  
Author(s):  
A.M. Abdul-Kader ◽  
Y.A. El-Gendy ◽  
Awad A. Al-Rashdi ◽  
A.M. Salem

The effect of ion beam bombardment on the optical and mechanical properties of ultra-high molecular weight polyethylene (UHMWPE) was investigated. UHMWPE polymer samples were bombarded with 150 keV N2ions under vacuum at room temperature to high fluences ranging from 1x1016to 2x1017ions cm-2. The untreated as well as treated samples were investigated by ultraviolet-visible (UV-Vis) spectrophotometer and Vickers micro-hardness techniques. The direct and indirect optical band gap decreased from 2.9 and 1.65 eV for pristine sample to 1.7 and 1 eV for those bombarded with N2ion beam at the highest fluence, respectively. With increasing ion fluence, an increase in the number of carbon atoms per conjugation length, N and number of carbon atoms per cluster, M in a formed cluster were observed. A significant improvement in surface hardness was obtained by increasing the ion fluence.


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