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Статті в журналах з теми "MoS2 nanosheets"
1
Wang, Hao, Xiaojie Xu, and Talgar Shaymurat. "Effect of Different Solvents on Morphology and Gas-Sensitive Properties of Grinding-Assisted Liquid-Phase-Exfoliated MoS2 Nanosheets." Nanomaterials 12, no. 24 (December 18, 2022): 4485. http://dx.doi.org/10.3390/nano12244485.
Повний текст джерелаАнотація:
Grinding-assisted liquid-phase exfoliation is a widely used method for the preparation of two-dimensional nanomaterials. In this study, N-methylpyrrolidone and acetonitrile, two common grinding solvents, were used during the liquid-phase exfoliation for the preparation of MoS2 nanosheets. The morphology and structure of MoS2 nanosheets were analyzed via scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. The effects of grinding solvents on the gas-sensing performance of the MoS2 nanosheets were investigated for the first time. The results show that the sensitivities of MoS2 nanosheet exfoliation with N-methylpyrrolidone were 2.4-, 1.4-, 1.9-, and 2.7-fold higher than exfoliation with acetonitrile in the presence of formaldehyde, acetone, and ethanol and 98% relative humidity, respectively. MoS2 nanosheet exfoliation with N-methylpyrrolidone also has fast response and recovery characteristics to 50–1000 ppm of CH2O. Accordingly, although N-methylpyrrolidone cannot be removed completely from the surface of MoS2, it has good gas sensitivity compared with other samples. Therefore, N-methylpyrrolidone is preferred for the preparation of gas-sensitive MoS2 nanosheets in grinding-assisted liquid-phase exfoliation. The results provide an experimental basis for the preparation of two-dimensional materials and their application in gas sensors.
2
Seo, Dong-Bum, Tran Trung, Sung-Su Bae, and Eui-Tae Kim. "Improved Photoelectrochemical Performance of MoS2 through Morphology-Controlled Chemical Vapor Deposition Growth on Graphene." Nanomaterials 11, no. 6 (June 17, 2021): 1585. http://dx.doi.org/10.3390/nano11061585.
Повний текст джерелаАнотація:
The morphology of MoS2 nanostructures was manipulated from thin films to vertically aligned few-layer nanosheets on graphene, in a controllable and practical manner, using metalorganic chemical vapor deposition. The effects of graphene layer and MoS2 morphology on photoelectrochemical (PEC) performance were systematically studied on the basis of electronic structure and transitions, carrier dynamic behavior, and PEC measurements. The heterojunction quality of the graphene/vertical few-layer MoS2 nanosheets was ensured by low-temperature growth at 250−300 °C, resulting in significantly improved charge transfer properties. As a result, the PEC photocurrent density and photoconversion efficiency of the few-layer MoS2 nanosheets significantly increased upon the insertion of a graphene layer. Among the graphene/MoS2 samples, the few-layer MoS2 nanosheet samples exhibited shorter carrier lifetimes and smaller charge transfer resistances than the thin film samples, suggesting that vertically aligned nanosheets provide highly conductive edges as an efficient pathway for photo-generated carriers and have better electronic contact with graphene. In addition, the height of vertical MoS2 nanosheets on graphene should be controlled within the carrier diffusion length (~200 nm) to achieve the optimal PEC performance. These results can be utilized effectively to exploit the full potential of two-dimensional MoS2 for various PEC applications.
3
Solomon, Getachew, Raffaello Mazzaro, Vittorio Morandi, Isabella Concina, and Alberto Vomiero. "Microwave-Assisted vs. Conventional Hydrothermal Synthesis of MoS2 Nanosheets: Application towards Hydrogen Evolution Reaction." Crystals 10, no. 11 (November 16, 2020): 1040. http://dx.doi.org/10.3390/cryst10111040.
Повний текст джерелаАнотація:
Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.
4
Ahmadi, Zabihi, Li, Fakhrhoseini, and Naebe. "A Hydrothermal-Assisted Ball Milling Approach for Scalable Production of High-Quality Functionalized MoS2 Nanosheets for Polymer Nanocomposites." Nanomaterials 9, no. 10 (October 1, 2019): 1400. http://dx.doi.org/10.3390/nano9101400.
Повний текст джерелаАнотація:
The most known analogue of graphene, molybdenum disulfide (MoS2) nanosheet, has recently captured great interest because it can present properties beyond graphene in several high technological applications. Nonetheless, the lack of a feasible, sustainable, and scalable approach, in which synthesizing and functionalization of 2H-MoS2 nanosheets occur simultaneously, is still a challenge. Herein, a hydrothermal treatment has been utilised to reduce the effect of breaking mechanisms on the lateral size of produced nanosheets during the ball milling process. It was demonstrated that the hydrothermal pre-treatment led to the initial intercalation of an organic molecule such as 4,4’-diaminodiphenyl sulfone (DDS) within the stacked MoS2 sheets. Such a phenomenon can promote the horizontal shear forces and cause sliding and peeling mechanisms to be the dominated ones during low energy ball milling. Such combined methods can result in the production of 2H functionalized MoS2 nanosheets. The resultant few layers showed an average lateral dimension of more than 640 nm with the thickness as low as 6 nm and a surface area as high as 121.8 m2/g. These features of the synthesised MoS2 nanosheets, alongside their functional groups, can result in fully harnessing the reinforcing potential of MoS2 nanosheets for improvement of mechanical properties in different types of polymeric matrices.
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Zhang, Liang, Fujian Zhou, Guofa Lei, Bingyu Ge, Yuan Li, Guolin Yu, Longhao Zhao, Bojun Li, and Erdong Yao. "Synthetic Method and Oil Displacement Capacity of Nano-MoS2." Geofluids 2022 (July 13, 2022): 1–10. http://dx.doi.org/10.1155/2022/7150916.
Повний текст джерелаАнотація:
Nanomaterials can be used to emulsify and reduce the fluid viscosity, reduce pore pressure, and increase injection volume. Therefore, nanomaterials have a great potential in the enhanced oil recovery. However, the current research on nanooil flooding materials mostly focuses on the evaluation of the oil-displacing effect, and the lack of research on the size of the oil-displacing materials for tight oil is obvious. In this work, 1T phase molybdenum disulfide nanosheets were prepared by one-step hydrothermal method, which were further modified with CTAB powders to obtain MoS2-CTAB nanosheet powders. Combined with SEM, TEM, and AFM methods, the nanosheets were optimized based on the appearance and morphology. The stability, wetting reversal, and oil displacement capacity of selected nanosheets were tested. The results show that the best experimental condition to synthesize small-sized molybdenum disulfide is 200°C in the weak acid environment through 12 h. Due to the steric hindrance effect of the CATB molecule, the size and interlayer gap of MoS2 nanosheets increased slightly after modification. The layer gap reaches to 0.7 nm, and the number of stacked layers is 3~4 layers. Strong Raman bands are observed at 137 cm-1, 291 cm-1, and 391 cm-1, which indicates that the synthesized product is 1T MoS2. The modified MoS2 nanosheets in aqueous solution have better dispersion than the unmodified one. After the Zeta test, it was found that the absolute value after modification became lower, indicating that the modification of nano-MoS2 was effective. Moreover, the MoS2-CTAB can complete the wetting reversal within 4 h and make the interfacial tension reach 0.89 mN/m at 0.005 wt%, which greatly reduces the capillary pressure. The enhanced oil recovery effect of MoS2-CTAB nanosheets increased by 85.7% compared with that before modification and 62.5% higher compared with pure surfactant.
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Hai, Zhen Yin, Jian Gong Du, Chen Yang Xue, Dan Feng Cui, Mohammad Karbalaei Akbari, and Serge Zhuiykov. "Engineering the Surface Structure of MoS2 Nanosheets by Carbon-Doping with Rich Defects to Tune UV-Visible Light Absorption Property." Key Engineering Materials 735 (May 2017): 185–88. http://dx.doi.org/10.4028/www.scientific.net/kem.735.185.
Повний текст джерелаАнотація:
A facile doping method utilizing inexpensive raw materials was proposed to achieve variation in optical bandgap and UV-visible light absorption property of MoS2 nanosheets. Carbon-assistant heating with degreasing cotton has demonstrated the development of carbon-doped MoS2 nanosheets with enhanced rich defects. The results obtained shown that modified MoS2 nanosheets with the lateral width of ~600 nm are exhibited shift of the intensively blue peaks of photo-luminescence (PL) comparing to those MoS2 nanosheets with a lateral dimension of larger than 1 μm. Optical bandgap of the carbon-doped MoS2 nanosheets was found to be broader than that of the pure MoS2 nanosheets and the prepared samples also exhibited a broadband UV-visible light absorption property.
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Huang, Wenjing, Yuta Sunami, Hiroshi Kimura, and Sheng Zhang. "Applications of Nanosheets in Frontier Cellular Research." Nanomaterials 8, no. 7 (July 12, 2018): 519. http://dx.doi.org/10.3390/nano8070519.
Повний текст джерелаАнотація:
Several types of nanosheets, such as graphene oxide (GO) nanosheet, molybdenum disulfide (MoS2) and poly(l-lactic acid) (PLLA) nanosheets, have been developed and applied in vitro in cellular research over the past decade. Scientists have used nanosheet properties, such as ease of modification and flexibility, to develop new cell/protein sensing/imaging techniques and achieve regulation of specific cell functions. This review is divided into three main parts based on the application being examined: nanosheets as a substrate, nanosheets as a sensitive surface, and nanosheets in regenerative medicine. Furthermore, the applications of nanosheets are discussed, with two subsections in each section, based on their effects on cells and molecules. Finally, the application prospects of nanosheets in cellular research are summarized.
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Zhang, Bo, Zhenhai Wang, Xiangfeng Peng, Zhao Wang, Ling Zhou, and QiuXiang Yin. "A Novel Route to Manufacture 2D Layer MoS2 and g-C3N4 by Atmospheric Plasma with Enhanced Visible-Light-Driven Photocatalysis." Nanomaterials 9, no. 8 (August 8, 2019): 1139. http://dx.doi.org/10.3390/nano9081139.
Повний текст джерелаАнотація:
An atmospheric plasma treatment strategy was developed to prepare two-dimensional (2D) molybdenum disulfide (MoS2) and graphitic carbon nitride (g-C3N4) nanosheets from (NH4)2MoS4 and bulk g-C3N4, respectively. The moderate temperature of plasma is beneficial for exfoliating bulk materials to thinner nanosheets. The thicknesses of as-prepared MoS2 and g-C3N4 nanosheets are 2–3 nm and 1.2 nm, respectively. They exhibited excellent photocatalytic activity on account of the nanosheet structure, larger surface area, more flexible photophysical properties, and longer charge carrier average lifetime. Under visible light irradiation, the hydrogen production rates of MoS2 and g-C3N4 by plasma were 3.3 and 1.5 times higher than the corresponding bulk materials, respectively. And g-C3N4 by plasma exhibited 2.5 and 1.3 times degradation rates on bulk that for methyl orange and rhodamine B, respectively. The mechanism of plasma preparation was proposed on account of microstructure characterization and online mass spectroscopy, which indicated that gas etching, gas expansion, and the repulsive force of electron play the key roles in the plasma exfoliation. Plasma as an environmentally benign approach provides a general platform for fabricating ultrathin nanosheet materials with prospective applications as photocatalysts for pollutant degradation and water splitting.
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Liang, Hongda, Zheng Peng, Xiao Peng, Yufeng Yuan, Teng Ma, Yiwan Song, Jun Song, and Junle Qu. "Fluorescence life-time imaging microscopy (FLIM) monitors tumor cell death triggered by photothermal therapy with MoS2 nanosheets." Journal of Innovative Optical Health Sciences 12, no. 05 (September 2019): 1940002. http://dx.doi.org/10.1142/s1793545819400029.
Повний текст джерелаАнотація:
Recently, photothermal therapy (PTT) has been proved to have great potential in tumor therapy. In the last several years, MoS2, as one novel member of nanomaterials, has been applied into PTT due to its excellent photothermal conversion efficacy. In this work, we applied fluorescence lifetime imaging microscopy (FLIM) techniques into monitoring the PPT-triggered cell death under MoS2 nanosheet treatment. Two types of MoS2 nanosheets (single layer nanosheets and few layer nanosheets) were obtained, both of which exhibited presentable photothermal conversion efficacy, leading to high cell death rates of 4T1 cells (mouse breast cancer cells) under PTT. Next, live cell images of 4T1 cells were obtained via directly labeling the mitochondria with Rodamine123, which were then continuously observed with FLIM technique. FLIM data showed that the fluorescence lifetimes of mitochondria targeting dye in cells treated with each type of MoS2 nanosheets significantly increased during PTT treatment. By contrast, the fluorescence lifetime of the same dye in control cells (without nanomaterials) remained constant after laser irradiation. These findings suggest that FLIM can be of great value in monitoring cell death process during PTT of cancer cells, which could provide dynamic data of the cellular microenvironment at single cell level in multiple biomedical applications.
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Karimi, Loghman. "Combination of mesoporous titanium dioxide with MoS2 nanosheets for high photocatalytic activity." Polish Journal of Chemical Technology 19, no. 2 (June 1, 2017): 56–60. http://dx.doi.org/10.1515/pjct-2017-0028.
Повний текст джерелаАнотація:
Abstract This study presents a facile approach for the preparation of MoS2 nanosheet decorated by porous titanium dioxide with effective photocatalytic activity. Mesoporous titanium dioxide nanostructures first synthesized by a hydrothermal process using titanium (III) chloride and then the MoS2/TiO2 were prepared through mixing of MoS2 nanosheet with mesoporous titanium dioxide under ultrasonic irradiation. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET) analysis. The results showed that the nanocomposite has mesoporous structure with specific surface area of 176.4 m2/g and pore diameter of 20 nm. The as-prepared MoS2/TiO2 nanocomposites exhibited outstanding photocatalytic activity for dye degradation under sunlight irradiation, which could be attributed to synergistic effect between the molybdenum disulfide nanosheet and mesoporous titanium dioxide. The photocatalytic performance achieved is about 2.2 times higher than that of mesoporous TiO2 alone. It is believed that the extended light absorption ability and the large specific surface area of the 2D MoS2 nanosheets in the nanocomposite, leading to the enhanced photocatalytic degradation activity.
Дисертації з теми "MoS2 nanosheets"
1
Feng, Xinliang, Jian Zhang, Tao Wang, Pan Liu, Shaohua Liu, Renhao Dong, Xiaodong Zhuang, and Mingwei Chen. "Engineering water dissociation sites in MoS2 nanosheets for accelerated electrocatalytic hydrogen production." Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30309.
Повний текст джерелаАнотація:
Earth-abundant MoS2 is widely reported as a promising HER electrocatalyst in acidic solutions, but it exhibits extremely poor HER activities in alkaline media due to the slow water dissociation process. Here we present a combined theoretical and experimental approach to improve the sluggish HER kinetics of MoS2 electrocatalysts through engineering the water dissociation sites by doping Ni atoms into MoS2 nanosheets. The Ni sites thus introduced can effectively reduce the kinetic energy barrier of the initial water-dissociation step and facilitate the desorption of the −OH that are formed. As a result, the developed Ni-doped MoS2 nanosheets (Ni-MoS2) show an extremely low HER overpotential of ∼98 mV at 10 mA cm−2 in 1 M KOH aqueous solution, which is superior to those (>220 mV at 10 mA cm−2) of reported MoS2 electrocatalysts.
2
Feng, Xinliang, Jian Zhang, Tao Wang, Pan Liu, Shaohua Liu, Renhao Dong, Xiaodong Zhuang, and Mingwei Chen. "Engineering water dissociation sites in MoS2 nanosheets for accelerated electrocatalytic hydrogen production." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-224286.
Повний текст джерелаАнотація:
Earth-abundant MoS2 is widely reported as a promising HER electrocatalyst in acidic solutions, but it exhibits extremely poor HER activities in alkaline media due to the slow water dissociation process. Here we present a combined theoretical and experimental approach to improve the sluggish HER kinetics of MoS2 electrocatalysts through engineering the water dissociation sites by doping Ni atoms into MoS2 nanosheets. The Ni sites thus introduced can effectively reduce the kinetic energy barrier of the initial water-dissociation step and facilitate the desorption of the −OH that are formed. As a result, the developed Ni-doped MoS2 nanosheets (Ni-MoS2) show an extremely low HER overpotential of ∼98 mV at 10 mA cm−2 in 1 M KOH aqueous solution, which is superior to those (>220 mV at 10 mA cm−2) of reported MoS2 electrocatalysts.
3
Ries, Lucie. "Functionalized two-dimensional (2D) MoS2 nanosheets as building blocks for water purification membranes." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2019. http://www.theses.fr/2019ENCM0009.
Повний текст джерелаАнотація:
Les technologies de séparation par membranes jouent un rôle important dans divers domaines tels que le traitement de l’eau, la séparation de produits chimiques et de gaz dans de nombreux domaines industriels ou encore l’industrie alimentaire. L’accent a récemment été mis sur les matériaux bidimensionnels(2D) pour les applications membranaires, car leur épaisseur atomique et leur espacement limité entre les couches pourraient théoriquement améliorer les performances de séparation. Les nanofeuillets eux-mêmes ou l’empilement de plusieurs feuillets peuvent former des membranes sélectives. L’empilement multicouche de monofeuillets sous forme de membrane nanolaminée crée des capillaires 2D (ou nanocanaux) capables de tamiser efficacement les espèces chimiques en fonction de leur taille. Des exemples récents ont été rapportés dans la littérature démontrant le potentiel des matériaux 2D en tant que membranes multicouches ou monocouches pour le tamisage moléculaire (222; 260; 466; 204), la séparation de gaz (219; 246; 190),la production d’énergie (467) et le dessalement de l’eau de mer (198; 194). Parmi les différentes membranes 2D nanolaminées, l’oxyde de graphène (GO) est le matériau le plus étudié, et le tamisage moléculaire au sein de sa structure est principalement dicté par la taille de ses capillaires 2D (222). Malheureusement,l’hydrophilie importante des nanofeuillets rend les membranes de GO instables en milieu aqueux, et la difficulté de contrôler la largeur des capillaires entre les nanofeuillets limite l’utilisation de ces membranes pour le traitement des eaux. D’autres matériaux 2D tels que les nanofeuillets exfoliées de dichalcogénures de métaux de transition (TMD) constituent des plateformes attrayantes pour la réalisation de membranes nanolaminées.Des travaux récents menés sur des membranes nanolaminées en disulfure de molybdène (MoS2) ont montré sa stabilité améliorée (3). Dans le cadre de cette thèse, nous avons étudié les performances d’un nouveau type de membranes nanolaminées en MoS2 pour lesquelles la chimie de surface des feuillets est précisément contrôlée (14). Afin d’évaluer le rôle de la chimie de surface,nous avons exploré l’impact de la fonctionnalisation covalente sur le tamisage moléculaire pour la purification de l’eau (plus particulièrement le dessalement et l’élimination des micropolluants) (14). Nos résultats ouvrent de nouvelles voies pour ajuster avec précision les capacités de séparation des membranes à base de matériaux 2DMembrane separation technology plays an important role in various fields including water treatment, chemicals and gas separation for numerous industrial fields, and food processing. There has been a renewed focus on two-dimensional(2D) materials for membrane application since their atomic thicknessand confined interlayer spacing could theoretically lead to enhanced separative performances. Either the single nanosheets themselves, or the stackingof multiple sheets can form selective membranes. The multilayer assembly of single nanosheets – forming nanolaminate membranes – creates 2D capillaries(or nanochannels) that can efficiently sieve chemical species depending ontheir size.Recent examples have been reported in the literature demonstrating the potential of 2D materials as multi- or single-layer membranes for molecular sieving(222; 260; 466; 204), gas separation (219; 246; 190), energy harvesting (467)and water desalination (198; 194).Among the different building blocks of nanolaminate membranes made of two-dimensional materials (2D), graphene oxide (GO) has been studied as a candidate for molecular sieving via size-limited diffusion in the 2D capillaries (222). Unfortunately the high hydrophilicity of GO nanosheets makes GO membranes unstable in water, while the poor control of the capillary width between the nanosheets limits the water permeance of the membranes. Other 2D materials such as exfoliated nanosheets of transition metal dichalcogenides (TMDs)constitute attractive platforms for the realization of nanolaminate membranes.Recent works carried out on nanolaminate membranes made of molybdenum disulfide (MoS2) have demonstrated improved stability (3). Within this thesis we have studied the performance of a novel type of MoS2 nanolaminate membranes with well-controlled surface chemistry of the nanosheets (14). Inorder to assess the role of surface chemistry, we explored the impact of covalent functionalization on molecular sieving toward water purification (i.e. desalination and micropollutant removal) (14). Our results open novel directions to finely tune the sieving behavior of membranes based on 2D materials
4
Al-Dulaimi, Naktal. "Rhenium disulfide and rhenium-doped MoS2 thin films from single source precursors." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/rhenium-disulfide-and-rheniumdoped-mos2-thin-films-from-single-source-precursors(16f715f7-392a-43f5-b201-64106517d319).html.
Повний текст джерелаАнотація:
The doping of rhenium into molybdenum disulfide was achieved by Aerosol Assisted Chemical Vapour Deposition (AACVD) from single source precursors. Rhenium can be studied as a model for immobilization of radioactive technetium-99 (99Tc) in MoS2. The metals Mo(IV), Re(IV), and Tc(IV) have similar ionic radii 0.65, 0.63 and 0.65 Å respectively, and their Shannon-Prewitt crystal radii 0.79, 0.77 and 0.79 Å Hence demonstrating the potential storage of nuclear waste in geologic like formations in of groundwater may be possible. The interaction between the nuclear waste forms and groundwater, which could lead to release and transport low concentrations or vapour of radionuclides to the near field, as a result, decomposition of engineered barriers. The molecular precursors [Mo(S2CNEt2)4], [Re3(μ-SiPr)3(SiPr)6], [Re(S2CC6H5)(S3CC6H5)2], and [Re2(μ-S)2(S2CNEt2)4] have been used to deposit Re-doped MoS2 thin films. Mo-doped ReS2 alloyed, polycrystalline thin films were synthesised using [Re(S2CC6H5)(S3CC6H5)2], [Mo(S2CNEt2)4] via AACVD, adding with a low concentration of Mo source for the first time . We reported as well a new way for production of ultrathin ReS2 nanosheets by coupling bottom up processing AACVD with top-down LPE. This is important in synthetic pathways for the production of rare transition dichalcogenide, also, our processing methodology is potentially scalable and thus could be a way to commercial exploitation. Characterisation of produced materials performed by pXRD, SEM, TEM, STEM, EDX, ICP and Raman spectroscopy.
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Gaben, Loic. "Fabrication et caractérisation de transistors MOS à base de nanofils de silicium empilés et à grille enrobante réalisés par approche Gate-Last pour les noeuds technologiques sub-7 nm." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT095/document.
Повний текст джерелаАнотація:
La diminution de la taille des transistors actuellement utilisés en microélectronique ainsi que l’augmentation de leurs performances demeure encore au centre de toutes les attentions. Cette thèse propose d’étudier et de fabriquer des transistors à base de nanofils empilés. Cette architecture avec des grilles enrobantes est l’ultime solution pour concentrer toujours plus de courant électrique dans un encombrement minimal. Les simulations ont par ailleurs révélé le potentiel des nanofeuillets de silicium qui permettent à la fois d’optimiser l’espace occupé tout en proposant des performances supérieures aux dispositifs actuels. L’importance de l’ajout de certaines étapes de fabrication a également été soulignée. En ce sens, deux séries d’étapes de fabrication ont été proposées : la première option vise à minimiser le nombre de variations par rapport à ce qui est aujourd’hui en production tandis que la deuxième alternative offre potentiellement de meilleures performances au prix de développements plus importants. Les transistors ainsi fabriqués proposent des performances prometteuses supérieures à ce qui a pu être fabriqué dans le passé notamment grâce à l’introduction de contraintes mécaniques importantes favorables au transport du courant électriqueThe future of the transistors currently used in Microelectronics is still uncertain: shrinking these devices while increasing their performances always remains a challenge. In this thesis, stacked nanowire transistors are studied, fabricated and optimized. This architecture embeds gate all around which is the ultimate solution for concentrating always more current within a smaller device. Simulations have shown that silicon nanosheets provide an optimal utilization of the space with providing increased performances over the other technologies. Crucial process steps have also been identified. Subsequently, two process flows have been suggested for the fabrication of SNWFETs. The first approach consists in minimizing the number of variations from processes already in mass production. The second alternative has potentially better performances but its development is more challenging. Finally, the fabricated transistors have shown improved performances over state-of-the-art especially due to mechanical stress induced for improving electric transport
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Sholeh, Mohammad, and 莫哈末. "Preparation and Characterization of Few-layer MoS2 Nanosheets." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/04439932220963451432.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
化學工程系
103
Exfoliation of bulk MoS2 via Li intercalation is an attractive route to large-scale preparation of MoS2 few-layers and it can be used to realize their unique properties in practical applications. In generally, solution-based exfoliation of layered materials results in flakes with lateral sizes of one micron or less on average. In this report, we performed the various preparations using a Li-intercalation method at room temperature to prepare MoS2 few-layers with various flake sizes according to dynamic light scattering (DLS) analysis. MoS2 few-layers with particle sizes ranging 85 to 145 nm are reported. We also characterize the few-layer MoS2 nanosheets by various microscopic and spectroscopic techniques.
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Mascarenhas, Xavier Mongiardim Pinto de. "MoS2 nanosheets as interlayer in Li-S batteries." Master's thesis, 2020. http://hdl.handle.net/10362/110347.
Повний текст джерелаАнотація:
This work has investigated the use of MoS2 nanosheets acting as an interlayer to effectively
block polysulfide shuttling (movement from cathode to the anode) in Li-S batteries.
In the first part of the work we exfoliated bulk MoS2 into a few layered MoS2 flakes, resulting
in increased surface area and improved electric properties, to achieve a better interlayer
performance by effectively trapping polysulfide (PS) in the cathode. This was done through
solvothermal lithium intercalation followed by water sonication, creating a reaction between
water and intercalated lithium to promote exfoliation.
In the second part was explored the electrochemical characterization of distinct Li-S test cells
(each with different interlayers), and compared to a standardized Li-S test cell. The afore
mentioned interlayers were spread either on to the cathode or the separator. Furthermore,
carbon black, bulk and exfoliated MoS2, were compared as active materials of the interlayers.
Bulk MoS2 exfoliation into thinner flake, resulted in a size reduction up to 56 times and a
decrease in the number of layers. The results of optical spectroscopy suggest effects of quantum
confinement. Furthermore, with XRD, was analytically demonstrated successful intercalation and
exfoliation. Then, through Raman and SEM analysis demonstrated evidence of thinner MoS2
structures.
On another hand, exfoliated MoS2 was spread on a sulfur cathode creating the interlayer that
successfully trapped polysulfides. This was showed through a 4 percentage points increase in
sulfur utilization for the first cycle, and an improvement of sulfur loss by cycle of 0.02%
retaining a good 99.4% coulombic efficiency. In addition a ΔE decreased of 45%, a result of
improved battery kinetics. Nonetheless a simple carbon black DL interlayer was also made using
a different solvent. However was observed a increase of sulfur utilization by 9% in the first cycle
and the same degradation of sulfur per cycle as the standard battery with an impressive CE of
99.7%.
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Gupta, Amit. "Aqueous and Non- aqueous dispersions of MoS2 Nanosheets." Thesis, 2018. https://etd.iisc.ac.in/handle/2005/5352.
Повний текст джерелаАнотація:
The focus of this thesis is an attempt
to provide a molecular perspective of the interactions of solvent and ligand molecules with
sonication assisted exfoliated MoS2 nanosheets in aqueous and non-aqueous dispersions.
In this thesis both experimental measurements, notably transmission electron microscopy
(TEM) and NMR spectroscopy, and molecular dynamics (MD) computer simulations
have been used.
This thesis consists of six chapters of which, Chapter 2 provides details of the experimental
procedures and techniques as well as the classical MD simulation methodologies
employed in this study. Transmission electron microscopy is critical to the present study.
The in-layer structure of the nanosheets obtained was examined in greater detail from the
phase corrected image reconstructed from a series of images recorded at different defocus
values. Details of the exit-wave reconstruction procedure are included as an appendix to
this chapter.
9
SINGH, MANJOT. "Study of biological interactions between water dispersed 2D-MoS2 nanosheets and live matter." Tesi di dottorato, 2020. http://www.fedoa.unina.it/13168/1/ManjotSingh32.pdf.
Повний текст джерелаАнотація:
The unique two dimensional structure and fascinating physicochemical properties of two dimensional materials (2D) have attracted tremendous attention worldwide in disease diagnosis and nano-biomedicine. As an analogue of 2D graphene, transition metal dichalcogenides (TMDs) such as 2D MoS2/WS2 nanosheets have been exploited as representative models in numerous applications ranging from nanoelectronics to the frontiers between nanomedicine and nanotechnology. The intriguing physical and chemical properties of 2D TMDs such as confinement in dimension due to their extreme thinness, stable free standing atomic crystal nanosheets without any substrate, unparalleled surface area to volume ratio, highly biocompatible and flexibility in functionalization with different biological molecules makes them potentially favorable candidate for many biomedical applications.
To get an insight into the biological and environmental fate of these engineered 2D nanosheets, it is very crucial to understand the nano-bio interactions at a prior level. Basically, the biological response to 2D nanomaterials is governed by material-specific behavior which further can be understood by the fundamental physicochemical properties of that material. Generally, three fundamental interaction modes are studied to analyze the biological impact of a given nanomaterial: a) chemical interactions, b) electronic and surface redox reactions and c) very unique physical and mechanical interactions. In general, 2DMs have shown wide range of behaviors with respect to these three modes of interactions at bio-nanosheet interface studies. Among these three modes, physical and mechanical interaction represents a unique way to study the biological response of 2D TMD nanosheets because of their high surface area to volume ratio, surface charge tuning and polarity. To exploit the full potential of 2D TMD nanosheets in biological applications, it is highly required that the given nanomaterial to be highly biocompatible, reproducible in the relevant physiological medium, flexibility in functionalization and with minimum cytotoxicity to the normal cells. In such a case and from the materials perspective, highly versatile, scalable, cost efficient and green fabrication techniques are required to obtain 2D nanosheets with the desired properties. To accomplish this aim, among various fabrication techniques reported for 2D TMDs such as chemical vapor deposition, electrochemical exfoliation, lithium intercalation, hydrothermal, sol-gel and liquid phase exfoliation, the latter one is the most versatile, scalable and cost effective technique for the production of few-layer nanosheets (1–10 stacked monolayers), with low monolayer content. Particularly in this technique, a careful optimization of exfoliation parameters such as, choice of green solvents, initial concentration of the solution, exfoliation time and controlled centrifugation for size and thickness selection of 2D nanosheets is very crucial to understand their environmental impact and behavior in biological media.
To this aim, my PhD project is focused on the noticeable progress on green and scalable production of MoS2 nanosheets in water as a pure solvent, having stability up to three weeks or more by carefully optimizing critical exfoliation parameters. Such a long stability time in water, which is a non-trivial result, is crucial to test the impact of 2DMs with biological live matter in its native context, as experiments aimed at these goals may take a few days or even longer to be completed. Thus, we stress that our innovative preparation of naked MoS2 nanosheets in water solvent represents an essential step ahead for an appropriate characterization of 2DMs – live matter interactions in its natural environment.
Till date, our group has investigated the biological interactions of bare MoS2 nanosheets with three different kinds of human cells, two tumoral, MCF7 (breast cancer) and U937 (leukemia), and one normal, HaCaT (epithelium), and two different kinds of Salmonella- ATCC 14028 and wild type S.typhimurium. It is worth noting that while MCF, and HaCaT cells have been already partly investigated with respect to their interactions with MoS2 nanosheets, U937-MoS2 interactions are completely unknown so far. Yet, MCF7 (Breast Cancer), Hela (Human Cervical Cancer), PC3 (Human Prostate Cancer), SMCC-7721 (Human Hepatocellular Carcinoma), B16 (Mouse Melanoma) and A549 (Human Lung Carcinoma) as cancer cell lines have been also recently tested as models by other research groups for the interactions between human cells and 2D functionalized nanomaterials of various composition, there including 2D Black Phosphorus nanosheets, 2D Boron nanosheets, 2D Antimonene quantum dots, 2D Antimonene nanosheets and Tin Sulfide nanosheets.
Here, we found a very interesting and novel result from our experiments: the impact of MoS2 nanoflakes was found to be quite different in normal from cancer cell lines. While the latter cells revealed a significant cytotoxic effect based on a very large increase of cell death, the former were essentially unaffected in this respect and only showed some mechanical damage when morphologically analyzed by SEM microscopy. This cytotoxic effect was also found to be dependent on the concentration and layer number of 2D nanoflakes. In the near future, this preliminary analysis might open up new routes for significant applications of MoS2 nanosheets as targeted anti-cancer systems. This analysis was further extended to bacteria and viruses. Particularly, we have investigated the mechanical interaction of 2D MoS2 nanoflakes with two different types of Salmonella typhimurium (ATCC 14028 and wild-type) which is a very serious Gram negative facultative anaerobe causing gastroenteritis in humans and in some cases it also results in serious neurological abnormalities with very high mortality rate. SEM analysis performed after the incubation of the complex system revealed significant damage to the bacterial morphology and leakage of intra-cellular components from the bacterial structure. Both of the salmonella types when treated with 2D MoS2 nanosheets, showed that the sharp edges of the nanoflakes can cut and/or damage bacterial membrane leading to an evident bactericidal effect.
Additionally, with a motive to deposit MoS2 nanosheets onto a patterned or machined substrate, particularly silicon because of its widely explored technological significance and usage in various laser processing techniques, we have first investigated the surface structuring of silicon using femtosecond laser pulses with a broad range of repetition rates (10 Hz – 200 kHz). Careful selection of various experimental conditions results in the formation of surface patterns which paves the way for numerous interesting applications. In view of this, I have introduced some preliminary results of LPE exfoliated MoS2 nanosheets deposited onto patterned silicon substrate for investigating non-linear optics of 2D nanosheets based on their thickness and given lateral size, in ongoing projects chapter at the end of this thesis.
Also, enthused from the synergistic impact of 2D MoS2 nanosheets on S. typhimurium, we are currently investigating the potential interaction of the same on two other types of bacteria such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In this ongoing research, we have achieved a significant time and concentration dependent damage to bacterial morphology tested at different points. We have also extended our study to analyze the mechanical interaction of water exfoliated 2D MoS2 nanosheets on a very commonly effected contagious virus, Herpes Simplex Virus (HSV-1), which has shown a good percentage of virus inhibition treated with water exfoliated MoS2 nanosheets. In fact, further investigations are under study and some of the preliminary results have been added into the ongoing projects chapter of this thesis.
In order to understand the specific mechanism of action of 2D MoS2 nanosheets on the already tested tumor and normal human cells in this thesis, we have further extended our analysis in another ongoing project to go into deeper insights of 2D MoS2 nanosheets - live matter interaction using advanced Raman microscopy technique. The cell viability and the subsequent Raman microscopic analysis performed on the MoS2 nanosheets incubated with the similar human cell lines (MCF-7, U937 and HaCaT) revealed noteworthy results confirming the specific action of MoS2 nanosheets on tumor cell line (MCF-7 and U937), whereas very little or negligible effect on normal cell line (HaCaT).
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Wu, Man-Jyun, and 吳曼君. "Functionalization of MoS2 nanosheets with aptamer as FRET-based nanoprobe for biomolecular detection and cellular imaging." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/6b4mnb.
Повний текст джерелаАнотація:
碩士國立中山大學
化學系研究所
107
In this study, we propose that mono-layered MoS2 nanosheets (M-MoS2 NSs) were proven to be impulsively adsorb on thiolated DNA molucules, due to the existence of sulfur vacancy sites on the surface of MoS2, based on that ssDNA-capped M-MoS2 NSs are customized to detect perfectly matched target DNA that is hybridized with the complementary ssDNA, MoS2 NSs with thiolated DNA molecules can be further accomplished via a one-step process under the mild buffer and salt-free conditions. In addition to, the filling of thiolated DNA molecules in sulfur vacancy sites is thermodynamically favorable. Inspired by these findings, we reason that sulfur vacancies of exfoliated MoS2 NSs could directly bind to thiol-terminated complementary oligonucleotides that are designed to bind with fluorescence resonance energy transfer (FRET)-based DNA probes. To further improvement, liberated reporter flares form hairpin-shaped structures, causing quite high FRET efficiency, these flare/ssDNA-capped M-MoS2 NSs offered comparable sensitivity, good selectivity, and high-precision to quantification of potassium (K+) ion and also Adenosine Triphosphate (ATP). In addition to, M-MoS2 NSs were used as a vector to modify the thiolated oligonucleotide (cDNA-SH) on a nanosheet by ligand conjugation, and the aptamer (D-Apt-A) partially complementary to the cDNA-SH sequence. The end group-modified fluorescent probe (FAM and TAMRA), which are the donor (D) and acceptor (A) of Förster resonance energy transfer (FRET), respectively. In the presence of the analyte, D-Apt-A would be facilitate to capture and carry out the double-strand hybridization and then detach from the surface anchored cDNA of M-MoS2 NSs. The as-prepared flare/ssDNA-capped M-MoS2 NSs and G4 flare/ssDNA- and also Apt flare/ssDNA were shown to have practical applications in the quantitative determination of K+ in human plasma and ATP in erythrocytes as well as ratio metric fluorescent imaging of K+- and ATP-related reactions and TK1 mRNA in living cells along with real samples.
Книги з теми "MoS2 nanosheets"
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Burke, A., D. Carroll, Frank Torti, and S. V. Torti. Bifunctional nanomaterials for the imaging and treatment of cancer. Edited by A. V. Narlikar and Y. Y. Fu. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199533060.013.13.
Повний текст джерелаАнотація:
This article examines the potential of bifunctional nanomaterials for the imaging and treatment of cancer. Several nanomaterials possess properties desirable for a cancer therapy and have been the subject of research as anticancer agents. Those that have received the most attention include encapsulated iron oxides, single- and multiwalled carbon nanotubes, gold nanorods and gold nanoshells. This article first considers thermal ablative therapy incancer, focusing on the mechanisms of thermotoxicity and thermoresistance before discussing a number of nanomaterials with applications for cancer treatment. In particular, it evaluates the use of nanomaterials in thermal therapy. It also looks at gold nanoshells and nanorods, taking into account their physical properties, and concludes with an assessment of iron-oxide nanoparticles and future directions for nanomaterials as multifunctional agents for cancer therapy.
Частини книг з теми "MoS2 nanosheets"
1
Bhandavat, R., L. David, U. Barrera, and G. Singh. "Large-Scale Synthesis of MoS2 -Polymer Derived SiCN Composite Nanosheets." In Ceramic Transactions Series, 45–52. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118511428.ch4.
Повний текст джерела
2
Yadav, Sarita. "Enhancement in Optical Absorbance of ZnO Nanoparticles by Introducing MoS2 Nanosheets." In Springer Proceedings in Physics, 77–82. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2592-4_9.
Повний текст джерела
3
Hu, Jianyue, Minglin Li, Weidong Wang, and Longlong Li. "Molecular Dynamics Simulations on Nanoindentation Experiment of Single-Layer MoS2 Circular Nanosheets." In Advanced Mechanical Science and Technology for the Industrial Revolution 4.0, 333–39. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-4109-9_34.
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Biswas, Shreerupa, and Sapana Ranwa. "CVD-Grown MoS2 Nanosheets-Based Gas Sensor for Low-Limit Detection of NO2 Gas." In Lecture Notes in Electrical Engineering, 439–47. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2710-4_36.
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Nguyen, Van-Truong, Tien-Dat Hoang, Nguyen Thi Kim Ngan, Pham Minh Tan, and Dang Van Thanh. "Role of Electrolyte Media in the Exfoliation of MoS2 Nanosheets by Electrolysis Plasma-Induced Method." In Advances in Engineering Research and Application, 724–28. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-64719-3_78.
Повний текст джерела
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Chaudhary, Nahid, Abid, Manika Khanuja, and S. S. Islam. "Synthesis of 2D MoS2 Nanosheets by Facile Hydrothermal Method for Its Functioning as Multi Wavelength Optical Sensing." In Springer Proceedings in Physics, 1001–3. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-97604-4_153.
Повний текст джерела
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Chen, W., J. Xiang, Y. Gao, and Z. Zhang. "Effects of Graphene Oxide Content on the Reinforcing Efficiency of C–S–H Composites: A Molecular Dynamics Study." In Lecture Notes in Civil Engineering, 521–26. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_55.
Повний текст джерелаАнотація:
AbstractDetermining the graphene oxide (GO) content is the key to applying GO to reinforce the mechanical performance and durability of cementitious composites. However, most of the previous studies are conducted from the perspective of experiments and lack elaboration on the mechanism of the GO-reinforced cementitious composite under different GO content. Hence, we investigated the effect of GO content on the reinforcing efficiency of calcium–silicate–hydrate (C–S–H) to trade off the enhancement of GO in cementitious composites and the corresponding economic benefits. The results demonstrated that an appropriate number of GO nanosheets can reinforce the cementitious composite with simultaneous high enhancing efficiency and economic benefits. The microdamage evolution of GO/C–S–H composites and the GO reinforcing mechanisms are reported. Our findings deepen the understanding of the enhancing mechanisms of GO embedded in C–S–H nanocomposites and help to determine the suitable GO content in practical engineering.
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Kumar, Praveen, and Amit Jaiswal. "2D Molybdenum Disulfide (MoS2 ) Nanosheets: An Emerging Antibacterial Agent." In Recent Trends and The Future of Antimicrobial Agents - Part 2, 172–89. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815123975123010011.
Повний текст джерелаАнотація:
The development of resistance against antibiotics in microorganisms has led to the search for alternatives that can effectively kill microbes and will have a lesser probability of the generation of resistance. In this regard, nanomaterials have emerged as protagonists demonstrating efficient antibacterial activities against drug-resistant strains. Amongst nanomaterials, 2D nanosheets have attracted attention as an antibacterial agent due to their sheet-like features, having sharp edges and corners which can pierce through bacterial membranes, subsequently leading to membrane damage. The present chapter discusses the antibacterial potential of one such 2D material, transition metal dichalcogenides, specifically MoS2 nanosheets and their composites. A brief discussion about the synthesis of MoS2 nanosheets is presented, and a detailed overview of its application as an antibacterial agent is illustrated. The mechanism of action of antibacterial activity of 2D MoS2 nanosheets is discussed, which shows that these nanosheets can cause bacterial cell death through membrane damage and depolarization, metabolic inactivation and generation of reactive oxygen species (ROS). Further, the photothermal property and the intrinsic peroxidase-like activity in certain conditions can also show antibacterial activity, which is summarized in the chapter along with the biocompatibility evaluation.
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Khosroupour Arabi, Mostafa, and Morteza Ghorbanzadeh Ahangari. "Heavy Metals Adsorption by Nanosheet: Mechanism and Effective Parameters." In Advances in Nanosheets [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.1001599.
Повний текст джерелаАнотація:
Nowadays, scientists are working on removing heavy metals from the environment. Among the methods for heavy metals removal such as precipitation, evaporation, electroplating and ion exchange, which have many disadvantages, adsorption is the cost effective and environmental friendly technique. Using nanosheets as the base materials for the adsorption because of their large surface area and high adsorption capacity is broadened. Carbon products (Graphene), boron nitride materials (BNM), transition metal dichalcogenides (TMDs), layered double hydroxiades (LDHs) and MXene are most well-known nanosheets, which have used for heavy metal ions removal from aqueous solutions. In this review, experimental and simulation studies on nanosheet adsorbents are presented to pinpoint the importance of this group of nano-materials on water/wastewater treatment technology. Molecular dynamics (MD) and density functional theory (DFT) are the most common simulation methods for demonstration of adsorption mechanism of nanosheets. In addition, synthesis methods, adsorption mechanism, adsorption performance, and effective parameters of nanosheets and novel techniques to improve the adsorption capability and regeneration of adsorbents are introducing. This study indicate that nanosheets can regenerate over a number of adsorption/desorption cycles. With all the advantages of nanosheets, it should be noted that their use in larger industrial scales should be further investigated.
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A. Tabbakh, Thamer, Prashant Tyagi, Deepak Anandan, Michael J. Sheldon, and Saeed Alshihri. "Boron Nitride Fabrication Techniques and Physical Properties." In Characteristics and Applications of Boron [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106675.
Повний текст джерелаАнотація:
The III-nitride semiconductors are known for their excellent extrinsic properties like direct bandgap, low electron affinity, and chemical and thermal stability. Among III-nitride semiconductors, boron nitride has proven to be a favorable candidate for common dimension materials in several crystalline forms due to its sp2- or sp3-hybridized atomic orbitals. Among all crystalline forms, hexagonal (h-BN) and cubic (c-BN) are considered as the most stable crystalline forms. Like carbon allotropes, the BN has been obtained in different nanostructured forms, e.g., BN nanotube, BN fullerene, and BN nanosheets. The BN nanosheets are a few atomic layers of BN in which boron and nitrogen are arranged in-planer in hexagonal form. The nanostructure sheets are used for sensors, microwave optics, dielectric gates, and ultraviolet emitters. The most effective and preferred technique to fabricate BN materials is through CVD. During the growth, BN formation occurs as a bottom-up growth mechanism in which boron and nitrogen atoms form a few layers on the substrate. This technique is suitable for high quality and large-area growth. Although a few monolayers of BN are grown for most applications, these few monolayers are hard to detect by any optical means as BN is transparent to a wide range of wavelengths. This chapter will discuss the physical properties and growth of BN materials in detail.
Тези доповідей конференцій з теми "MoS2 nanosheets"
1
Qu, Ming, Tuo Liang, Jirui Hou, Weipeng Wu, Yuchen Wen, and Lixiao Xiao. "Ultralow Concentration of Amphiphilic Molybdenum Disulfide Nanosheets for Enhanced Oil Recovery-Research and Field Application." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206260-ms.
Повний текст джерелаАнотація:
Abstract Recently, spherical nanoparticles have been studied to enhance oil recovery (EOR) worldwide due to their remarkable properties. However, there is a lack of studies of nanosheets on EOR. In this work, we synthesize the amphiphilic molybdenum disulfide nanosheets through a straightforward hydrothermal method. The octadecyl amine (ODA) molecules were grafted onto the surfaces of molybdenum disulfide nanosheets due to the presence of active sites over the surfaces of MoS2 nanosheets. The synthesized amphiphilic molybdenum disulfide nanosheets (ODA-MoS2 nanosheets) are approximate 67 nm in width and 1.4 nm in thickness. The effects of ultralow concentration ODA-MoS2 nanosheets on the dynamic wettability change of solid surfaces and emulsion stability were also studied and discussed. Besides, the core flooding experiments were also conducted to reveal the adsorption rules and the oil displacement effects of ultralow concentration ODA-MoS2 nanosheets. Experimental results indicate that the oil-wet solid surface (a contact angle of 130°) can transform into the neutral-wet solid surface (a contact angle of 90°) within 120 hrs after 50 mg/L ODA-MoS2 nanosheets treatment. In addition, micro-scale emulsions in size of 2 µm can be formed after the addition of ODA-MoS2 nanosheets by adsorbing onto the oil-water interfaces. The desorption energy of a single ODA-MoS2 nanosheet from the oil-water interface to the bulk phase is proposed. When the concentration of ODA-MoS2 nanosheets is 50 mg/L, the emulsions are the most stable. Core flooding results demonstrate that the ultimate residue of ODA-MoS2 nanosheets in porous media is less than 11%, and the highest increased oil recovery of around 16.26% is achieved. Finally, the production performance of ultralow concentration of ODA-MoS2 nanofluid (50 mg/L) in the application of Daqing Oilfield is summarized and discussed.
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Camellini, Andrea, Eugenio Cinquanta, Christian Martella, Carlo Mennucci, Alessio Lamperti, Giulio Cerullo, Giuseppe Della Valle, Alessandro Molle, Francesco Buatier de Mongeot, and Margherita Zavelani-Rossi. "Optical characterization of anisotropic MoS2 nanosheets." In 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE, 2017. http://dx.doi.org/10.1109/cleoe-eqec.2017.8087717.
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Wu, Guodong, Yanchi Liu, Maieryemuguli Anwaier, Erdong Yao, Hongda Ren, and Yuan Li. "Small Sizes of Molybdenum Disulfide Nanosheets As Heavy Oil Viscosity Reducers." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-78776.
Повний текст джерелаАнотація:
Abstract The high content of asphaltenes and colloids in heavy oil lead to their high viscosity, making it difficult to exploit and transport. Nanomaterials have become an important additive in reducing viscosity of crude oil. In this work, a series of amphiphilic molybdenum dioxide (MoS2) nanosheets are developed to reduce the viscosity of crude oil by an ultralow concentration aqueous solution. Firstly, nanosheets were synthesized by the hydrothermal methods. The influence factors such as raw material ratio, temperature and time were investigated. Then, SEM are used to systemically characterize the morphology and structure of MoS2 nanosheets. Then, the properties (i.e., size, viscosity reduction, and interfacial activity) of MoS2 nanosheets are tested. The relationship between these properties and viscosity reduction abilities were studied. Finally, based on viscosity reduction testing results, optimal MoS2 nanosheets formulation and dosage are determined. By controlling the stirring and temperature, hydrophilic MoS2 nanosheets with sizes from 40 nm to 160 nm were synthesized, respectively. Modifying them with oleyl amine, the amphiphilic nanosheets can be obtained. SEM show that they are materials with layered nano-structure and commonly composed of 8–10 layers. These nanosheets have good interfacial activity, wetting and emulsifying ability. By adding 100 ppm of MoS2 nanosheets to the mixture of heavy oil and water, the viscosity of these system can fall from > 880 mPa·s to 9 mPa·s. The smaller the size of the MoS2 nanosheets is, the better the viscosity reduction ability will be. The optimal using dosage of these nanosheets is 300–400 ppm, and the optimal size is 40–60 nm. It is predicted that nanosheets will gradually become a new field for the development of heavy oil.
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Li, Han, Huaqiang Wu, Bo Wang, and He Qian. "Field emission properties of vertically aligned MoS2 nanosheets." In 2015 IEEE International Conference on Electron Devices and Solid-State Circuits (EDSSC). IEEE, 2015. http://dx.doi.org/10.1109/edssc.2015.7285143.
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Zhang, Kaiyu, Jirui Hou, and Zhuojing Li. "Improved Gelation Performance of an Acidic Low-Polymer Loading Zirconium Cross-Linked CMHPG Fracturing Fluid by Surface Functionalized 1T-Phase Molybdenum Disulfide Nanosheets." In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204308-ms.
Повний текст джерелаАнотація:
Abstract The low and ultra-low permeability reservoirs in China, such as the Changqing, Jidong, and Daqing peripheral oil fields, often apply CO2 as a flooding medium to enhance oil recovery. A serial of water-rock interactions will be occurred among the CO2, formation rock, and formation water under the HT/HP conditions. The pH value of the formation will be converted to acidity accordingly. As a side effect, the traditional guar-based fracturing fluids in an alkaline range, such as the borate cross-linked hydroxypropyl guar gum (HPG), cannot result in an effective hydrofracturing operation due to the incompatibility. Consequently, developing an acidic fracturing fluid system with a satisfactory performance is an imperative. Acidic fracturing fluids, such as the zirconium cross-linked carboxymethyl hydroxypropyl guar gum (CMHPG), can protect the formation during the hydrofracturing process from the damage arising from the swelling and migration of the clay particles. However, the shortcomings of the uncontrollable viscosity growth and the irreversible shear-thinning behavior limit the large-scale use of the acidic fracturing fluids. In this work, a novel organic zirconium cross-linker synthesized in the laboratory was applied to control and delay the cross-link reaction under the acidic condition. The ligands coordinated to the zirconium center were the L-lactate and ethylene glycol. The thickener used was the CMHPG at a low loading of 0.3% (approximately 25 pptg). Meanwhile, the surface functionalized metallic phase (1T-phase) molybdenum disulfide (MoS2) nanosheets were employed to improve the rheological performance of the zirconium cross-linked CMHPG fracturing fluid. The modification reagent utilized was the L-cysteine. The morphology, structure, and property of the fabricated functionalized 1T-MoS2 (Cys-1T-MoS2) nanosheets were systematically characterized using the transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) measurements. The results of the characterization tests demonstrated a successful functionalization of the 1T-MoS2 nanosheets with L-cysteine. Then, the effects of this new nanosheet-enhanced zirconium cross-linked CMHPG fracturing fluid systems with different cross-linker and nanosheet loadings on gelation performance were systematically assessed employing the Sydansk bottle testing method combined with a rheometer under the controlled-stress or controlled-rate modes. The results indicated that the nanosheet-enhanced fracturing fluid had a desirable delayed property. Compared with the blank fracturing fluid (without nanosheets), the nanosheet-enhanced fracturing fluid had a much better shear-tolerant and shear-recovery performance.
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Qu, M. "Mechanisms of Nanofluid Based Modification MoS2 Nanosheet for Enhanced Oil Recovery." In Indonesian Petroleum Association 44th Annual Convention and Exhibition. Indonesian Petroleum Association, 2021. http://dx.doi.org/10.29118/ipa21-e-162.
Повний текст джерелаАнотація:
Recently, much attention has been directed towards the applications of nanofluids for enhanced oil recovery (EOR). Here, amphiphilic molybdenum disulfide (KH550-MoS2) nanosheets were synthesized using a hydrothermal approach. The physicochemical properties and potential EOR of ultra-low concentration KH550-MoS2 nanofluids were systematically investigated under reservoir conditions at Changqing Oilfield (China) (temperature~55℃ and salinity~7.8×104 mg/L). Interfacial tension (IFT), wettability change, and emulsion stability were measured to evaluate the physicochemical properties of the KH550-MoS2 nanofluids. The results showed that ultra-low concentration of KH550-MoS2 nanofluid (50 mg/L) could decrease IFT to 2.6 mN/m, change the contact angle (CTA) from 131.2° to 51.7° and significantly enhance emulsion stability. Core flooding experiments were conducted to determine the dynamic adsorption loss law and the oil displacement efficiency of KH550-MoS2 nanofluid. The results indicated that the ratio of cumulative produced KH550-MoS2 nanosheets to the total injected KH550-MoS2 nanosheets (CNR) reached 91.5% during flooding in low permeability reservoirs. Moreover, ultra-low concentration KH550-MoS2 nanofluid can increase the oil displacement efficiency by 14% after water driven. This study shows the physicochemical properties of the KH550-MoS2 amphiphilic nanofluid and offers a novel high- efficiency amphiphilic nanofluid for EOR
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Di Bartolomeo, Antonio, Francesca Urban, Aniello Pelella, Alessandro Grillo, Laura Iemmo, Enver Faella, and Filippo Giubileo. "Electrical transport in two-dimensional PdSe2 and Mos2 nanosheets." In 2020 IEEE 20th International Conference on Nanotechnology (IEEE-NANO). IEEE, 2020. http://dx.doi.org/10.1109/nano47656.2020.9183617.
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Ankush, Jashangeet Kaur, and Navdeep Goyal. "Size selection of MoS2 nanosheets through liquid exfoliation technique." In DAE SOLID STATE PHYSICS SYMPOSIUM 2018. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5113025.
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Chaudhary, Nahid, Karthick Raj, Anjali Harikumar, Honey Mittal, and Manika Khanuja. "Comparative study of photocatalytic activity of hydrothermally synthesized ultra-thin MoS2 nanosheets with bulk MoS2." In PROCEEDINGS OF INTERNATIONAL CONFERENCE ON RECENT TRENDS IN MECHANICAL AND MATERIALS ENGINEERING: ICRTMME 2019. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0025756.
Повний текст джерела
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Kapatel, Sanni, and C. K. Sumesh. "One pot sono-chemical synthesis of 2D layered MoS2 nanosheets." In INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC 2015): Proceeding of International Conference on Condensed Matter and Applied Physics. Author(s), 2016. http://dx.doi.org/10.1063/1.4946182.
Повний текст джерела