Molybdenum Disulfide Nanoparticles Research Articles

MoS2 nanoparticles induce behavioral alteration and oxidative stress mediated cellular toxicity in the social insect Oecophylla smaragdina (Asian weaver ant)

The study evaluates molybdenum disulfide (MoS2) nanoparticles (NPs) induced oxidative stress during cellular toxicity in an invertebrate in vivo system, the weaver ant. The lethal concentration was checked and LC50 was obtained as 50 µg/mL. Feeding assay and the photoluminescence activity confirmed the ingestion of MoS2 NPs by the organism. Behavioral assays showed altered grooming behavior in the MoS2 NP fed ants. A drastic decrease in the hemocyte count in the MoS2 NP fed ants revealed the anti-proliferative role of MoS2. This was further confirmed by 5-bromo-2′-deoxyuridine (BrdU) labeling assay. MoS2 NPs induced apoptotic activity was also observed in the hemocytes by acridine orange/ethidium bromide (AO/EB) staining. The level of oxidative stress during cellular toxicity was observed. An increased reactive oxygen species (ROS) level was observed in the MoS2 NP fed ants when compared to the control group. The increased activity of superoxide dismutase (SOD) and the lipid peroxidation (LPO) product were observed. While, the activities of catalase (CAT) and glutathione-s-transferase (GST) and the glutathione content (GSH) were decreased by MoS2 NPs. The transcript levels of SODs, CAT and GST were up regulated in the treated group. Our results suggest that MoS2 NPs induced oxidative stress mediates the cellular toxicity in the foragers of the weaver ant.

Scrutinization of different shaped nanoparticle of molybdenum disulfide suspended nanofluid flow over a radial porous fin

Purpose The purpose of this paper is to study the thermal behaviour of radial porous fin wetted with nanofluid containing different shaped nanoparticles in the presence of natural convection and radiation. Here, the nanofluid suspended with molybdenum disulfide nanoparticle with base fluid as water is considered. The influence of non-spherical nanoparticles such as platelet, cylinder, brick and blade shapes is also investigated. Design/methodology/approach The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. Findings The flow natures of the pertinent parameter are represented graphically and discussed their physical significance. From the validation of obtained outcome, it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate. Originality/value The present paper deals with an analysis of the flow of molybdenum disulfide nanoparticles suspended in water over a porous fin of a radial profile. The effect of differently shaped nanoparticles on the heat transfer enhancement through the radial porous fin is investigated for the first time. The natural convection and radiation effects are also considered. The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. The effect of pertinent parameters on temperature field is examined. From the validation of obtained outcome it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.

Simulation and Sensitivity Analysis of Molybdenum Disulfide Nanoparticle Production Using Aspen Plus

The sensitivity analysis of molybdenum disulfide nanoparticles synthesis process is studied using Aspen Plus with the aim of investigating the effect of reactants’ amounts on the production of molybdenum disulfide nanoparticles. The adopted approach consists in simulating the synthesis process based on experimental data, obtained at laboratory scale followed by sensitivity analysis with respect to the following precursors: ammonium heptamolybdate, elemental sulfur, and hydrazine used as a reducing agent. The sensitivity analysis revealed that the precursors have more significant impact on the obtained amount of molybdenum disulfide compared to hydrazine. The obtained result showed that the approach adopted in the study might be of interest for further investigation of the process design and scaling-up.

Q-switched erbium-doped fiber laser with molybdenum disulfide (MoS2) nanoparticles on D-shaped fiber as saturable absorber

In this study, short [Formula: see text]-switching laser pulses are generated by drop-casting two-dimensional Molybdenum Disulfide (MoS[Formula: see text] nanoparticles as saturable absorbers (SA) on a side polished optical fiber in a [Formula: see text]-band laser cavity. The proposed laser is capable of generating highly stable [Formula: see text]-switched laser pulses at the wavelength of 1559.42[Formula: see text]nm with a maximum repetition rate of 73.96[Formula: see text]kHz, and a minimum pulse width of 1.93[Formula: see text][Formula: see text]s. The relatively high signal-to-noise ratio of 58.7[Formula: see text]dB indicates a highly stable output. The proposed SA can be applied in a variety of fields due to its ease of manufacturing and cost-effectiveness as well as its robust and compact design.

Experimental investigation of MoS2/diesel oil nanofluid thermophysical and rheological properties

Thermophysical and tribological properties of traditional lubricant has important role in proper performance of industrial equipment and transportation vehicles. Diesel oil is wide used lubricant with very limited studies on its properties and this study aimed to evaluate the tribological and thermo-physical properties of diesel oil containing molybdenum disulfide (MoS2) nanoparticles. The nanoparticles were dispersed at 0.1, 0.4 and 0.7 wt% in each pure diesel oil. To assess the friction and wear properties of MoS2 nano-lubricant, pin-on-disc friction and wear tester were used. In this study, it was proved that mixing MoS2 nanoparticles in diesel oil increases nanofluids viscosity, viscosity index; the highest viscosity and viscosity index were found at 0.7 wt%. The findings also showed that the additives involved no significant anti-friction and anti-wear properties effect at different concentrations compared to the pure diesel oil. Furthermore, the MoS2 nanoparticles in diesel oil could not significantly alter the friction factor values in comparison with pure oil. The experimental results indicated that the addition of MoS2 nanoparticles to diesel oil had no significant effects on anti-wear properties and also concentration impact on the tribological performance of lubricant is negligible.

Exploring the effects of boron nitride coating on the thermal stability and photoluminescence properties of molybdenum disulfide nanospheres

Here, we sprang up a novel approach to synthesize molybdenum disulfide nanoparticles coated by hexagonal boron nitride via high-temperature sintering technique under floating ammonia gas at 900 °C for 3 h MoS2-BN nanocomposites have significant thermal stability with an oxidation temperature of 715 °C, indicating that its antioxidant performance increased by 217% compared with the pure MoS2 nanospheres. Additionally, the strong red PL signal of MoS2-BN characterized by Steady state transient fluorescence spectrometer appears at ~678 nm at room temperature, its strength has reached 3.14 × 106 CPS, while the original MoS2 nanospheres shows almost no characteristics, demonstrating that the nanocomposites have excellent luminescent properties. Therefore, the improved properties of molybdenum disulfide materials encapsulated by hexagonal boron nitride (h-BN) expand the applications of MoS2 nanospheres in high temperature and optoelectronic devices, which could pave way for the h-BN encapsulated transition metal dichalcogenides (TMDCs).

Flexible HIV-1 Biosensor Based on the Au/MoS2 Nanoparticles/Au Nanolayer on the PET Substrate.

An electrochemical flexible biosensor composed of gold (Au), molybdenum disulfide nanoparticles (MoS2 NPs), and Au (Au/MoS2/Au nanolayer) on the polyethylene terephthalate (PET) substrate is developed to detect envelope glycoprotein GP120 (gp120), the surface protein of HIV-1. To fabricate the nanolayer on the PET substrate, Au is sputter coated on the flexible PET substrate and MoS2 NPs are spin coated on Au, which is sputter coated once again with Au. The gp120 antibody is then immobilized on this flexible electrode through cysteamine (Cys) modified on the surface of the Au/MoS2/Au nanolayer. Fabrication of the biosensor is verified by atomic force microscopy, scanning electron microscopy, and cyclic voltammetry. A flexibility test is done using a micro-fatigue tester. Detection of the gp120 is measured by square wave voltammetry. The results indicate that the prepared biosensor detects 0.1 pg/mL of gp120, which is comparable with previously reported gp120 biosensors prepared even without flexibility. Therefore, the proposed biosensor supports the development of a nanomaterial-based flexible sensing platform for highly sensitive biosensors with flexibility for wearable device application.

Tribological Properties of Composite Langmuir–Blodgett Coatings of OLEIC Acid with Molybdenum Disulfide Nanoparticles

Tribological properties of composite Langmuir–Blodgett monolayers of oleic acid (OA) with MoS2 nanoparticles formed on silicon surfaces by the horizontal precipitation method were studied. Incorporation of MoS2 (the average particle size [Formula: see text][Formula: see text]nm) into the structure of the layer was found to result in the increase of minimal area per molecule from 0.43[Formula: see text]nm2 to 0.58[Formula: see text]nm2 and wear stability of OA monolayer.

Magnetohydrodynamic flow of molybdenum disulfide nanofluid in a channel with shape effects

PurposeThe purpose of this paper is to examine the combined effects of thermal radiation and magnetic field of molybdenum disulfide nanofluid in a channel with changing walls. Water is considered as a Newtonian fluid and treated as a base fluid and MoS2 as nanoparticles with different shapes (spherical, cylindrical and laminar). The main structures of partial differential equations are taken in the form of continuity, momentum and energy equations.Design/methodology/approachThe governing partial differential equations are converted into a set of nonlinear ordinary differential equations by applying a suitable similarity transformation and then solved numerically via a three-stage Lobatto III-A formula.FindingsAll obtained unknown functions are discussed in detail after plotting the numerical results against different arising physical parameters. The validations of numerical results have been taken into account with other works reported in literature and are found to be in an excellent agreement. The study reveals that the Nusselt number increases by increasing the solid volume fraction for different shapes of nanoparticles, and an increase in the values of wall expansion ratio α increases the velocity profile f′(η) from lower wall to the center of the channel and decreases afterwards.Originality/valueIn this paper, a numerical method was utilized to investigate the influence of molybdenum disulfide (MoS2) nanoparticles shapes on MHD flow of nanofluid in a channel. The validity of the literature review cited above ensures that the current study has never been reported before and it is quite new; therefore, in case of validity of the results, a three-stage Lobattoo III-A formula is implemented in Matlab 15 by built in routine “bvp4c,” and it is found to be in an excellent agreement with the literature published before.

Influence of Adding CuO and MoS2 Nano-particles to Castor Oil and Moulding Oil on Tribological Properties

The tribological properties of adding copper oxide (CuO) and molybdenum disulfide (MoS2) nanoparticles powder in both organic (castor oil) and mineral oil (moulding oil) were investigated. These properties include coefficient of friction and wear between two surfaces, CK50 steel alloy and 2024-T4 aluminum alloy. The Nano lubricants were prepared by dispersing CuO and MoS2 nanoparticle powders at variable weight fractions 0.3, 0.5, 0.7, 1.0 and 2.0% in each oil lubricant. The friction and wear tests were carried out using a pin on the disk test principle by the vertical universal friction testing machine (MMW-1A). The instability problem with the lubricant suspension was solved by adding different weight fractions of GUM ARABIC, which leads to 2% of it gives more stable suspensions. The best results from both friction and wear Tribo tests are observed in 1%W of adding both nanoparticles to both oil lubricants. The formation of Tribo film due to the adsorption and adherence of Nano additives on the surfaces was responsible in reducing the wear properties. Hybrid (1%Wt CuO + 1Wt% MoS2) nanoparticles that added to both oils indicates more decreasing in friction and wear compared to the base oil. The coefficient of friction for hybrid Nano-particulate lubricants reduced to 81.7% and 76.03%, while the wear rate reduced to 93.17% and 92.23% compared to castor oil and moulding oil respectively as a base oil. The study provides insights into how Nano-lubricant additives could contribute towards tribological enhancement and improved product quality.

THE INFLUENCE OF NANO PARTICLES ADDITIVE ON TRIBOLOGICAL PROPERTIES OF AA2024-T4 COATED WITH TiN OR SiN THIN FILMS

In the current study, the radio frequency magnetron sputtering technique was used to sputter a thin layer of titanite nitride (TiN) or silicon nitride (SiN) on the surface of AA2024-T4 alloy. To investigate the wear behavior and coefficient of friction between coated aluminum alloy pin and a steel disc (Ck50) contact bodies, different percentages of Copper oxide (CuO) and molybdenum disulfide (MoS2) Nanoparticles were added to the sunflower and engine (HD 50) oils. The results reveal important enhancement in wear rate and coefficient of friction when Nanoparticles powder was added to the oil in comparison with dry and base oils conditions. The optimum results for wear rate and coefficient of friction were obtained at the 1%wt of both Nanoparticles additive. The results also show a significant enhancement in wear and friction conditions when the surface of the aluminum alloy pin was coated with TiN and SiN in comparison with the uncoated surface.

Resistive switching biodevice composed of MoS2-DNA heterolayer on the gold electrode

Biomolecules have been widely studied for bioelectronic application including biosensors, biomedical devices, biocomputation devices. Among them, the resistive switching biodevices have been developed to demonstrate the resistive switching function based on biomolecules. However, resistive switching biodevices developed so far have some limitations such as narrow voltage range and low stability for practical application. In this study, a heterolayer composed of carboxyl-modified molybdenum disulfide nanoparticles (MoS2) and DNA on the gold (Au) electrode was developed to achieve a wide voltage range and high stability at the nanoscale. To fabricate the resistive switching biodevices, a DNA layer was formed on the electrode through the thiol group on the DNA. The carboxyl-modified MoS2 was then immobilized on the DNA layer (MoS2-DNA heterolayer) through the EDC/NHS reaction. For analyzing the electrical properties, the scanning tunneling spectroscopy investigation showed the resistive switching function of a wide voltage range (4.0 V to −4.0 V) and high stability (10 days) on the MoS2-DNA heterolayer of Au electrodes. The conductivity dramatically increased when the voltage reached 2.4 V, whereas the conductivity abruptly decreased when the voltage reached 0.01 V. From results, we proposed that a MoS2-DNA heterolayer on Au electrode could be utilized as a nanoscale resistive switching layer for the development of nanoscale bioelectronic devices with a wide voltage range and high stability. Based on those advantages, the introduction of MoS2/DNA heterolayer can offer the new direction for development of novel bioelectronic devices.

Remarkable role of [formula omitted] on transportation of [formula omitted] hybrid nanoparticles influenced by thermal deposition and internal heat generation

The present work focuses on examining nanofluidic transport in presence of temperature dependent viscosity. In order to conduct a comparative investigation Silicon dioxide and Molybdenum disulfide nanoparticles are considered to be suspended in propylene glycol. Furthermore, heat transfer has been inspected for nano and hybrid nanofluids influenced by internal heat source/sink, thermal radiation, and heat dissipation. Additionally, the Cartesian coordinate system opts for mathematical formulation of governing equations. Moreover, similarity analysis is employed to obtain the system of highly nonlinear coupled equations which is solved numerically by means of shooting technique. The key findings include that nanofluid and hybrid nanofluid floe decelerates for increasing values of the viscosity parameter and magnetic parameter while a contrary trend was observed for the rising values of Grashof number. Volumetric fraction ϕ1 and ϕ2 contributed in decelerating fluid flow for plate-shaped particles of nanofluid as well as of hybrid nanofluid. Temperature distribution up surged for rising values of Biot number, Eckert number, viscosity parameter, magnetic parameter, heat generation parameter and lessened for rising values of radiation parameter, Grashof number. This trend was noted for SiO2 and MoS2−SiO2 nanofluids. Moreover, magnetic field, viscous dissipation and heat generation contributed in rising Nusselt number while opposite behavior was observed in presence of thermal radiation and convective boundaries. Furthermore, the maximum Nusselt number was attained for needle shape nanoparticles of MoS2−SiO2 and the minimum value was noted for plate-shaped SiO2 nanoparticles. Nanoparticle volumetric fractions play role in rising skin fraction of SiO2 nanofluid while it decreased in case of hybrid nanofluid. Moreover, minimum skin fraction was noted for needle-shaped nanoparticles of hybrid nanofluid and the maximum value was recorded for plate-shaped nanoparticles of SiO2 .

Effects of Different Shaped Nanoparticles on the Performance of Engine-Oil and Kerosene-Oil: A generalized Brinkman-Type Fluid model with Non-Singular Kernel

In the modern era, diathermic oils have been gotten the great attention from researchers due to its notable and momentous applications in engineering, mechanics and in the industrial field. The aim of this paper is to model the problem to augment the heat transfer rate of diathermic oils, specifically, Engine-oil (EO) and Kerosene-oil (KO) are taken. The present work is dedicated to examine the shape impacts of molybdenum-disulfide (MoS2) nanoparticles in the free convection magnetohydrodynamic (MHD) flow of Brinkman-type nanofluid in a rotating frame. The problem is modeled in terms of partial differential equations with oscillatory boundary conditions. The integer-order model is transformed to fractional-order model in time (Caputo-Fabrizio). The exact solutions are obtained using the Laplace transform technique. Figures are drawn to compare the different non-spherically shaped molybdenum-disulfide nanoparticles on secondary and primary velocities. The Nusselt number is computed in the tabular form and discussed in detail. It is worth noting that platelet and blade shape of MoS2 nanoparticle has more tendency to improve the heat transfer rate of both fluids as compared to nanoparticles with brick and cylinder shapes. It is also shown that the rate of heat transfer enhances 13.51% by adding MoS2 in engine oil which improved its lubrication properties.

A combined computational and experimental study of the adsorption of sulfur containing molecules on molybdenum disulfide nanoparticles

Abstract

Quantum-Chemical and Experimental Investigation of the Catalytic Activity of Nanosized Particles of Nickel-Promoted Molybdenum Disulfide in the Hydroconversion Process

The paper is devoted to the investigation of the catalytic properties of nickel-promoted molybdenum disulfide nanoparticles in the hydroconversion process. The formation of Mo and Ni compounds under hydroconversion conditions has been studied using chemical thermodynamics methods. Quantum-chemical calculations in the cluster approximation have confirmed the catalytic activity of MonNimSp nanoparticles in the reactions of hydrogen activation and aromatic-ring hydrogenation. It has been shown that the main role in the activation of hydrogen and the hydrogenation of aromatic rings is played by Mo- and Ni-containing active sites of the catalyst, respectively. To confirm theoretical assumptions, the yield of products of fuel oil hydroconversion on nanosized particles of the catalyst, nickel-promoted and in situ formed molybdenum disulfide, has been investigated. It has been shown that the promotion with nickel enhances the hydrogenating functions of the molybdenum-containing catalyst and lowers coke formation during hydroconversion.

Antifriction Properties of Plasma-Chemical Coatings Based on SiO2 with MoS2 Nanoparticles under Conditions of Spinning Friction on ShKh15 Steel

The antifriction properties of coatings in the form of a nanocomposite of a silica layer with molybdenum disulfide nanoparticles distributed in it, whose average sizes are 70, 64, 61, and 53 nm and concentrations are 80, 73, 68, and 62 wt %, respectively, grown via plasma-chemical deposition at atmospheric pressure on a 12Cr18Ni10Ti steel, are studied. The best tribotechnical properties are established for a SiO2 + 68% MoS2 coating (61 nm) which possesses the most stationary friction mode and a friction force two times lower as compared to a MoS2-free SiO2 coating.

Natural convection in polyethylene glycol based molybdenum disulfide nanofluid with thermal radiation, chemical reaction and ramped wall temperature

The aim of this study is to investigate the unsteady magnetohydrodynamic (MHD) flow of Casson nanofluid over an infinite oscillating vertical plate with ramped wall temperature. The effects of porosity, thermal radiation and first order chemical reaction have been considered. Polyethylene glycol (PEG) is chosen as base fluid which contained molybdenum disulfide (MoS2 ) nanoparticles. The Laplace transform technique is applied to the momentum, energy and concentration equations to obtain the closed form solutions. The obtained solutions are for both cases ramped and isothermal boundary conditions and compared graphically. From graphical analysis, it is observed that for isothermal plate, the magnitude of velocity, temperature and concentration profiles are greater than ramped wall temperature. Skin-friction, Nusselt number and Sherwood number are evaluated and presented in tabular forms. The effects of various embedded parameters on velocity, temperature and concentration profiles are discussed graphically.

Thin-Layered Molybdenum Disulfide Nanoparticles as an Effective Polysulfide Mediator in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are attractive as sulfur offers an order of magnitude higher charge-storage capacity than the currently used insertion-compound cathodes. However, their practical viability is hampered by low electrochemical stability and efficiency, which results from severe polysulfide (LiPS) shuttling during cycling. We present here thin-layered MoS2 nanoparticles (MoS2-NPs) synthesized through a one-pot method and coated onto a commercial polymeric separator (as MoS2-NP-coated separator) as an effective LiPS mediator, facilitated by the nanodimension, polar interactions, and the better edge-binding sites of the MoS2-NPs. The resulting MoS2-NPs have an interlayer spacing of 0.55 nm and are stacked with a few layers. At a sulfur loading of 4.0 mg cm-2, the Li-S cell with a MoS2-NP-coated separator attains a peak discharge capacity of 983 mA h g-1, improving the electrochemical utilization of sulfur. The cell is able to maintain a high capacity of 525 mA h g-1 after 150 cycles at a C/5 rate. The MoS2-NPs are able to effectively anchor the LiPS species to their large S2- anions, enhancing the redox accessibility of sulfur cathodes and enabling better capacity retention.

Molybdenum disulfide-based modifier for electrochemical detection of 4-nitrophenol

We report the synthesis, characterization, and electrochemical sensing application of molybdenum disulfide (MoS2) nanoparticles. The MoS2 nanoparticles have been prepared by the gas-solid reaction method, and they have been characterized using different techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis, photoluminescence, FTIR, Raman, and impedance spectroscopy. The electrocatalytic activity of MoS2 nanoparticles towards the reduction of 4-nitrophenol (4-NP) has been studied using cyclic voltammetry. The experimental parameters such as the effect of scan rate and pH have been optimized for the electrochemical detection of 4-NP. The linear relationship between the peak current and the concentration of 4-nitrophenol was found to be in the range of 4 × 10−6 M to 2 × 10−8 M with an impressive detection limit of 10 nM. The performance of MoS2-modified glassy carbon electrode towards 4-NP detection shows good stability, reproducibility with the recovery percentage of ~ 95%. The obtained results clearly indicate the potential application of MoS2 nanoparticles for the selective and sensitive electrochemical detection of 4-NP.