scholarly journals Production and Properties of Molybdenum Disulfide/Graphene Oxide Hybrid Nanostructures for Catalytic Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1865
Author(s):  
Zuzanna Bojarska ◽  
Marta Mazurkiewicz-Pawlicka ◽  
Stanisław Gierlotka ◽  
Łukasz Makowski
Keyword(s):  
Graphene Oxide ◽  
Molybdenum Disulfide ◽  
Carbon Nanomaterials ◽  
Analytical Techniques ◽  
Linear Sweep Voltammetry ◽  
Production Method ◽  
Physicochemical Analysis ◽  
Electrode System ◽  
Hybrid Nanostructures ◽  
Mos2 Nanoparticles

Molybdenum disulfide (MoS2) can be an excellent candidate for being combined with carbon nanomaterials to obtain new hybrid nanostructures with outstanding properties, including higher catalytic activity. The aim of the conducted research was to develop the novel production method of hybrid nanostructures formed from MoS2 and graphene oxide (GO). The nanostructures were synthesized in different weight ratios and in two types of reactors (i.e., impinging jet and semi-batch reactors). Physicochemical analysis of the obtained materials was carried out, using various analytical techniques: particle size distribution (PSD), thermogravimetric analysis (TGA), FT-IR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Due to the potential application of materials based on MoS2 as the catalyst for hydrogen evolution reaction, linear sweep voltammetry (LSV) of the commercial MoS2, synthesized MoS2 and the obtained hybrid nanostructures was performed using a three-electrode system. The results show that the developed synthesis of hybrid MoS2/GO nanostructures in continuous reactors is a novel and facile method for obtaining products with desired properties. The hybrid nanostructures have shown better electrochemical properties and higher onset potentials compared to MoS2 nanoparticles. The results indicate that the addition of carbon nanomaterials during the synthesis improves the activity and stability of the MoS2 nanoparticles.

scholarly journals Significance of Shape Factor in Heat Transfer Performance of Molybdenum-Disulfide Nanofluid in Multiple Flow Situations; A Comparative Fractional Study

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3711
Author(s):  
Asifa ◽  
Talha Anwar ◽  
Poom Kumam ◽  
Zahir Shah ◽  
Kanokwan Sitthithakerngkiet
Keyword(s):  
Heat Transfer ◽  
Skin Friction ◽  
Molybdenum Disulfide ◽  
Heat Transfer Rate ◽  
Shape Factor ◽  
Transfer Rate ◽  
Maximum Heat ◽  
Left Wall ◽  
Maximum Heat Transfer ◽  
Mos2 Nanoparticles

In this modern era, nanofluids are considered one of the advanced kinds of heat transferring fluids due to their enhanced thermal features. The present study is conducted to investigate that how the suspension of molybdenum-disulfide (MoS2) nanoparticles boosts the thermal performance of a Casson-type fluid. Sodium alginate (NaAlg) based nanofluid is contained inside a vertical channel of width d and it exhibits a flow due to the movement of the left wall. The walls are nested in a permeable medium, and a uniform magnetic field and radiation flux are also involved in determining flow patterns and thermal behavior of the nanofluid. Depending on velocity boundary conditions, the flow phenomenon is examined for three different situations. To evaluate the influence of shape factor, MoS2 nanoparticles of blade, cylinder, platelet, and brick shapes are considered. The mathematical modeling is performed in the form of non-integer order operators, and a double fractional analysis is carried out by separately solving Caputo-Fabrizio and Atangana-Baleanu operators based fractional models. The system of coupled PDEs is converted to ODEs by operating the Laplace transformation, and Zakian’s algorithm is applied to approximate the Laplace inversion numerically. The solutions of flow and energy equations are presented in terms of graphical illustrations and tables to discuss important physical aspects of the observed problem. Moreover, a detailed inspection on shear stress and Nusselt number is carried out to get a deep insight into skin friction and heat transfer mechanisms. It is analyzed that the suspension of MoS2 nanoparticles leads to ameliorating the heat transfer rate up to 9.5%. To serve the purpose of achieving maximum heat transfer rate and reduced skin friction, the Atangana-Baleanu operator based fractional model is more effective. Furthermore, it is perceived that velocity and energy functions of the nanofluid exhibit significant variations because of the different shapes of nanoparticles.

scholarly journals The Structure–Properties–Cytotoxicity Interplay: A Crucial Pathway to Determining Graphene Oxide Biocompatibility

2021 ◽  
Vol 22 (10) ◽  
pp. 5401
Author(s):  
Marta Dziewięcka ◽  
Mirosława Pawlyta ◽  
Łukasz Majchrzycki ◽  
Katarzyna Balin ◽  
Sylwia Barteczko ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Defense Mechanisms ◽  
Physicochemical Analysis ◽  
Experimental Models ◽  
Acheta Domesticus ◽  
Synthesis Process ◽  
Synthesis Methods ◽  
Toxicity Potential ◽  
Potential Applications

Interest in graphene oxide nature and potential applications (especially nanocarriers) has resulted in numerous studies, but the results do not lead to clear conclusions. In this paper, graphene oxide is obtained by multiple synthesis methods and generally characterized. The mechanism of GO interaction with the organism is hard to summarize due to its high chemical activity and variability during the synthesis process and in biological buffers’ environments. When assessing the biocompatibility of GO, it is necessary to take into account many factors derived from nanoparticles (structure, morphology, chemical composition) and the organism (species, defense mechanisms, adaptation). This research aims to determine and compare the in vivo toxicity potential of GO samples from various manufacturers. Each GO sample is analyzed in two concentrations and applied with food. The physiological reactions of an easy model Acheta domesticus (cell viability, apoptosis, oxidative defense, DNA damage) during ten-day lasting exposure were observed. This study emphasizes the variability of the GO nature and complements the biocompatibility aspect, especially in the context of various GO-based experimental models. Changes in the cell biomarkers are discussed in light of detailed physicochemical analysis.

Tribological Studies of Transmission Oil Dispersed With Molybdenum Disulfide and Tungsten Disulfide Nanoparticles

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
V. Srinivas ◽  
R. N. Thakur ◽  
A. K. Jain ◽  
M. Saratchandra Babu
Keyword(s):  
Molybdenum Disulfide ◽  
Size Variation ◽  
Tungsten Disulfide ◽  
Particle Size Analyzer ◽  
Transmission Oil ◽  
Mos2 Nanoparticles ◽  
The Stability ◽  
Friction And Wear Characteristics ◽  
Load Conditions ◽  
And Tungsten

This paper compares the tribological properties of transmission oil dispersed with molybdenum disulfide (MoS2) and tungsten disulfide (WS2) nanoparticles. Lubricant samples are prepared by dispersing MoS2 and WS2 nanoparticles in 0.5 wt.% in transmission oil. The nanoparticles are stabilized in the lubricant by surface modification with surfactant SPAN 80. The stability of the lubricant in terms of size variation of dispersed nanoparticles is evaluated using particle size analyzer. The antiwear, antifriction, and extreme pressure (EP) properties are tested on a four-ball wear tester and a comparison is made to assess the relative performance of MoS2 and WS2 nanoparticles. The friction and wear characteristics of lubricant dispersed with nanoparticles are strongly dependent upon the load taken into consideration. The lubricant dispersed with WS2 nanoparticles gave higher weld load and load wear index (LWI) than that of lubricant dispersed with MoS2 nanoparticles. The metallographic studies show that under high load conditions, the WS2 nanoparticles deposit more than MoS2 nanoparticles, thereby giving better performance at higher load conditions.

Ternary Composite of Molybdenum Disulfide-Graphene Oxide-Polyaniline for Supercapacitor

2021 ◽  
Author(s):  
Ke Qu ◽  
Yuqi Bai ◽  
Miao Deng
Keyword(s):  
Graphene Oxide ◽  
Molybdenum Disulfide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Light Emitting Diode ◽  
Rate Capability ◽  
Energy Storage And Conversion ◽  
Carbon Paper ◽  
Power Sources ◽  
X Ray

Abstract The ever-increasing need for small and lightweight power sources for use in portable or wearable electronic devices has spurred the development of supercapacitors as a promising energy storage and conversion system. In this work, a simple, facile and easy-to-practice method has been developed to employ carbon paper (CP) as the support to coat molybdenum disulfide (MoS2) and graphene oxide (GO), followed by electrodeposition of polyaniline (PANI) to render CP/MoS2-GO-PANI. The preparation parameters, such as amounts of MoS2, GO and number of aniline electropolymerization cycles, have been optimized to render CP/MoS2-GO-PANI the best capacitive performance. The as-prepared optimal CP/MoS2-GO-PANI is characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The supercapacitive properties of CP/MoS2-GO-PANI as an electrode have been evaluated electrochemically via cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy testing. CP/MoS2-GO-PANI delivers a specific capacitance of 255.1 F/g at 1.0 A/g and exhibits excellent rate capability under larger current densities. Moreover, a symmetrical supercapacitor is assembled and three are connected in series to power a light-emitting diode for ~15 minutes, demonstrating the promising application potential of CP/MoS2-GO-PANI-based supercapacitor.

scholarly journals General Analytical Schemes for the Characterization of Pectin-Based Edible Gelled Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Maryam Haghighi ◽  
Karamatollah Rezaei
Keyword(s):  
Image Analysis ◽  
Three Dimensional ◽  
Analytical Techniques ◽  
Physicochemical Analysis ◽  
Visual Observation ◽  
Scientific Data ◽  
Rheological Measurement ◽  
Rheological Measurements ◽  
Analytical Approaches

Pectin-based gelled systems have gained increasing attention for the design of newly developed food products. For this reason, the characterization of such formulas is a necessity in order to present scientific data and to introduce an appropriate finished product to the industry. Various analytical techniques are available for the evaluation of the systems formulated on the basis of pectin and the designed gel. In this paper, general analytical approaches for the characterization of pectin-based gelled systems were categorized into several subsections including physicochemical analysis, visual observation, textural/rheological measurement, microstructural image characterization, and psychorheological evaluation. Three-dimensional trials to assess correlations among microstructure, texture, and taste were also discussed. Practical examples of advanced objective techniques including experimental setups for small and large deformation rheological measurements and microstructural image analysis were presented in more details.

scholarly journals The Role of Bio-Extracted Reduced Graphene Oxide in the Crystallization Kinetics of Chitosan Bio-Polymer

2021 ◽  
pp. 1-4
Author(s):  
Solomon L Joseph ◽  
◽  
Agumba O John ◽  
Fanuel M Keheze ◽  
◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Carbon Nanomaterials ◽  
High Strength ◽  
Limiting Factor ◽  
Reduced Graphene ◽  
Electrical Conductivities ◽  
Coating Method ◽  
Potential Applications ◽  
New Applications

Carbon nanomaterials have recently attracted wide scientific applications due to their tunable properties. These novel materials act as best fillers that can provide substantial benefits due to their high strength, thermal conductivity, and electrical conductivities. With their huge applications as bulk materials, when implemented in polymer matrix as fillers, they give rise to new promising materials with which their properties can be tuned to suit a particular application. Besides the development of these new nanocomposite materials, there exist some challenges which must be fully surpassed to explore the potentiality of application of carbon-based nanocomposites. Reduced graphene oxide is one of the carbon derivatives which has attracted the current advancement in technology, and recently, it found its new applications in super capacitors used in electronic industries. The limiting factor for its exploration is the affordability. New and affordable sources of these graphene-based nanomaterial have to be devised, for fully realization of their potential applications. In this study, reduced graphene oxide and the bio-polymer chitosan were extracted from the locally available bio waste materials. Nanocomposites were prepared at 50% rGO: chitosan ratio. The films were then prepared by spin coating method. Prepared films were subjected to morphological analysis. From the results, it was observed that rGO induced chitosan crystallization, which led to formation of dendritic structures. Cellulose nanocrystals have thus displayed temperature dependent positive uniaxial birefringence

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