scholarly journals Novel ternary nanocomposites of MWCNTs/PANI/MoS 2 : preparation, characterization and enhanced electrochemical capacitance

2018 ◽  
Vol 5 (1) ◽  
pp. 171365 ◽  
Author(s):  
Ranran Zhang ◽  
Yu Liao ◽  
Shuangli Ye ◽  
Ziqiang Zhu ◽  
Jun Qian
Keyword(s):  
Rate Capability ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Good Rate Capability ◽  
A Current

In this work, nanoflower-like MoS 2 grown on the surface of multi-walled carbon nanotubes (MWCNTs)/polyaniline (PANI) nano-stem is synthesized via a facile in situ polymerization and hydrothermal method. Such a novel hierarchical structure commendably promotes the contact of PANI and electrolyte for faradaic energy storage. In the meanwhile, the double-layer capacitance of MoS 2 is effectively used. The morphology and chemical composition of the as-prepared samples are characterized by scanning and transmission electron microscopies, X-ray diffraction and Fourier transform infrared spectra. The electrochemical performance of the samples is evaluated by cyclic voltammogram and galvanostatic charge–discharge measurements. It is found that the specific capacitance of the obtained MWCNTs/PANI/MoS 2 hybrid is 542.56 F g −1 at a current density of 0.5 A g −1 . Furthermore, the MWCNTs/PANI/MoS 2 hybrid also exhibits good rate capability (62.5% capacity retention at 10 A g −1 ) and excellent cycling stability (73.71% capacitance retention) over 3000 cycles.

scholarly journals Peroxide Electrochemical Sensor and Biosensor Based on Nanocomposite of TiO2 Nanoparticle/Multi-Walled Carbon Nanotube Modified Glassy Carbon Electrode

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 64 ◽  
Author(s):  
L. Andrés Guerrero ◽  
Lenys Fernández ◽  
Gema González ◽  
Marjorie Montero-Jiménez ◽  
Rafael Uribe ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Glassy Carbon ◽  
Sodium Dodecylsulfate ◽  
Modified Electrodes ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Before And After ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A hydrogen peroxide (H2O2) sensor and biosensor based on modified multi-walled carbon nanotubes (CNTs) with titanium dioxide (TiO2) nanostructures was designed and evaluated. The construction of the sensor was performed using a glassy carbon (GC) modified electrode with a TiO2–CNT film and Prussian blue (PB) as an electrocalatyzer. The same sensor was also employed as the basis for H2O2 biosensor construction through further modification with horseradish peroxidase (HRP) immobilized at the TiO2–fCNT film. Functionalized CNTs (fCNTs) and modified TiO2–fCNTs were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-Ray DifFraction (XRD), confirming the presence of anatase over the fCNTs. Depending on the surface charge, a solvent which optimizes the CNT dispersion was selected: dimethyl formamide (DMF) for fCNTs and sodium dodecylsulfate (SDS) for TiO2–fCNTs. Calculated values for the electron transfer rate constant (ks) were 0.027 s−1 at the PB–fCNT/GC modified electrode and 4.7 × 10−4 s−1 at the PB–TiO2/fCNT/GC electrode, suggesting that, at the PB–TiO2/fCNT/GC modified electrode, the electronic transfer was improved. According to these results, the PB–fCNT/GC electrode exhibited better Detection Limit (LD) and Quantification Limit (LQ) than the PB–TiO2/fCNT/GC electrode for H2O2. However, the PB film was very unstable at the potentials used. Therefore, the PB–TiO2/fCNT/GC modified electrode was considered the best for H2O2 detection in terms of operability. Cyclic Voltammetry (CV) behaviors of the HRP–TiO2/fCNT/GC modified electrodes before and after the chronoamperometric test for H2O2, suggest the high stability of the enzymatic electrode. In comparison with other HRP/fCNT-based electrochemical biosensors previously described in the literature, the HRP–fCNTs/GC modified electrode did not show an electroanalytical response toward H2O2.

scholarly journals Optimization of sulfate removal from wastewater using magnetic multi-walled carbon nanotubes by response surface methodology

2017 ◽  
Vol 76 (10) ◽  
pp. 2593-2602 ◽  
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Sedighi ◽  
Ehsan Jabbari
Keyword(s):  
Carbon Nanotubes ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Polynomial Equation ◽  
X Ray Diffraction ◽  
Adsorption Models ◽  
Sulfate Removal ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Abstract This paper reports a facile method for removal of sulfate from wastewater by magnetic multi-walled carbon nanotubes (MMWCNTs). Multi-walled carbon nanotubes and MMWCNTs were characterized by X-ray diffraction, Raman, transmission electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results of the analysis indicated that MMWCNTs were synthesized successfully. The MMWCNTs can be easily manipulated in a magnetic field for the desired separation, leading to the removal of sulfate from wastewater. Response surface methodology (RSM) coupled with central composite design was applied to evaluate the effects of D/C (adsorbent dosage per initial concentration of pollutant (mgadsorbent/(mg/l)initial)) and pH on sulfate removal (%). Using RSM methodology, a quadratic polynomial equation was obtained, for removal of sulfate, by multiple regression analysis. The optimum combination for maximum sulfate removal of 93.28% was pH = 5.96 and D/C = 24.35. The experimental data were evaluated by the Langmuir and Freundlich adsorption models. The adsorption capacity of sulfate in the studied concentration range was 56.94 (mg/g). It was found out that the MMWCNTs could be considered as a promising adsorbent for the removal of sulfate from wastewater.

scholarly journals Electrochemical Performance of FeF3·0.33H2O/MWCNTs Composite Cathode Synthesized by Solvothermal Process

2015 ◽  
Vol 18 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Yanli Zhang ◽  
Li Wang ◽  
Jianjun Li ◽  
Xiangming He ◽  
Lei Wen ◽  
...  
Keyword(s):  
High Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Composite Cathode ◽  
Solvothermal Reaction ◽  
Multi Walled Carbon Nanotubes ◽  
Energy Storage Applications ◽  
Walled Carbon Nanotubes ◽  
Structural Characterizations ◽  
Good Rate Capability

This paper reports a FeF3·0.33H2O/multi-walled carbon nanotubes (MWCNTs) composite for energy storage applications. The composite material is prepared by solvothermal reaction with FeF3·3H2O and MWCNTs as precursors, and FeF3·3H2O was removed of crystalliferous water and converted to FeF3·0.33H2O during solvothermal treatment. Structural characterizations show that FeF3·0.33H2O that crystalline with a diameter of about 30 nm were distributed in the network of MWCNTs. As a cathode material for lithium ion batteries, FeF3·0.33H2O/MWCNTs was superior to pure FeF3·0.33H2O in terms of high capacity (an initial capacity of 181 mAh g-1 in 2.0-4.3 V at 20 mA g-1), good cycleability (50% capacity retension at 50th cycle) and good rate capability (116 mAh g-1 at 100 mA g-1). The enhanced performances were attributed to the conductive MWCNT network which improved the electron transport ability and buffered volume change of the cathode.

Microstructural of Cr/MWCNT Composites and its Catalysis in Synthesis of Biodiesel

2012 ◽  
Vol 455-456 ◽  
pp. 1053-1059
Author(s):  
Xue Hai Fan ◽  
Guo Min Xiao
Keyword(s):  
Electron Microscopy ◽  
Potassium Dichromate ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs), potassium dichromate (K2Cr2O7) and sulphuric acid were used for the preparation of Cr/MWCNT composite by impregnation method. The composites were comprehensively characterized by transmission electron microscopy （TEM），energy dispersive X-ray analysis (EDX), infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal gravity analysis (TGA). Due to its unique electrical and structural properties, this composite was applied to the synthesis of biodiesel (FAME) as a catalyst, showing effectively catalytic performance.

scholarly journals Structural characterization of Fe–C coatings prepared by reactive triode-magnetron sputtering

2010 ◽  
Vol 25 (9) ◽  
pp. 1859-1869 ◽  
Author(s):  
Isabelle Jouanny ◽  
Valérie Demange ◽  
Jaafar Ghanbaja ◽  
Elisabeth Bauer-Grosse
Keyword(s):  
Magnetron Sputtering ◽  
Gas Flow ◽  
Carbon Matrix ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Electron Energy Loss

Fe1–xCx coatings were synthesized by triode magnetron sputtering of an iron target in a methane/argon atmosphere with a large range of composition (x = 0.3 to 0.6 ± 0.06). Film surfaces were characterized by grazing incidence x-ray diffraction, scanning and transmission electron microscopies, and electron energy loss spectroscopy, to study effects of the variation of the methane gas flow rate on their structural properties. The coatings were constituted of the ε-Fe3C carbide (x = 0.3 and 0.36), in which carbon atoms are in octahedral sites, and of nanocomposite structure constituted of disordered and crystalline carbide nanograins embedded in a carbon matrix made of an amorphous and poorly crystallized graphenelike material (x = 0.55 and 0.60). In situ annealing of the nanocomposite Fe0.45C0.55 coating led to the formation of carbides θ-Fe3C and Fe7C3 (with carbon atoms in prismatic sites) and C-rich cubic carbide possibly related to the τ2-Fe2C7 compound.

Carbon nanotubes and carbon fibers in a flash: an easy and convenient preparation of carbon nanostructures using a conventional microwave

2020 ◽  
Vol 98 (1) ◽  
pp. 49-55 ◽  
Author(s):  
María Fernanda Veloz-Castillo ◽  
Antonio Paredes-Arroyo ◽  
Gerardo Vallejo-Espinosa ◽  
José Francisco Delgado-Jiménez ◽  
Jeffery L. Coffer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Carbon Nanostructures ◽  
Glass Tube ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Application Fields ◽  
Walled Carbon Nanotubes

The growing interest in nanomaterials in different application fields calls for the implementation of simple, economically appealing, and efficient preparative methods. Among the wide variety of nanomaterials, carbon nanostructures have a special place due to their potential technological applications. Here, we present a fast, cheap, and easy-to-implement microwave-assisted method for the preparation of carbon nanotubes (CNTs) and carbon fibers (CFs) at room pressure conditions. The synthesis involves heating a mixture of graphite and ferrocene contained in a simple glass tube using a conventional microwave oven. A mixture of multi-walled carbon nanotubes (MWCNTs) and Fe3O4 magnetic nanoparticles were obtained quickly (less than 30 s) and in good yields. The products were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and Raman spectroscopy.

UV-Fenton Discoloration of Methyl Orange Using Fe3O4/MWCNTs as Heterogeneous Catalyst Obtained by an In Situ Strategy

2014 ◽  
Vol 618 ◽  
pp. 208-214 ◽  
Author(s):  
Tian Nuo Shi ◽  
Huan Yan Xu ◽  
Hong Zhou Chang
Keyword(s):  
Methyl Orange ◽  
Synergetic Effect ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Fenton Catalyst ◽  
Multi Walled Carbon Nanotubes ◽  
In Suit ◽  
Walled Carbon Nanotubes

As an innovative heterogeneous UV-Fenton catalyst nanocomposite, ferroferric oxide (Fe3O4) with inverse-spinel structure trapped by Multi-walled carbon nanotubes (MWCNTs) was successfully prepared by a facile and in-suit strategy in this study. The as-prepared products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). An active dye, Methyl Orange (MO) was employed as the target pollutant to evaluate the UV-Fenton efficiency of Fe3O4/MWCNTs nanocomposite. The effects of operating parameters, including solution pH, initial MO concentration, reaction temperature, initial H2O2concentration and catalyst dosage on MO discoloration were detailedly investigated. Control experiments indicated Fe3O4/MWCNTs exhibited higher ability for MO discoloration than bare Fe3O4under the same experimental conditions, which might be attributed to the synergetic effect between Fe3O4and MWCNTs.

SYNTHESIS AND CONTROL SIZE OF SnS2 NANOPARTICLES ON THE SURFACE MULTI-WALLED CARBON NANOTUBES

NANO ◽  
2010 ◽  
Vol 05 (03) ◽  
pp. 139-142 ◽  
Author(s):  
ROSTAM MORADIAN ◽  
BANDAR ASTINCHAP
Keyword(s):  
Carbon Nanotubes ◽  
Reaction Temperature ◽  
Acid Mixture ◽  
X Ray Diffraction ◽  
Ultrasound Waves ◽  
Tin Disulfide ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
And Control ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes have been decorated by SnS2 nanoparticles with different sizes using a simple chemical method. In this work, first multi-walled carbon nanotubes (MWCNTs) functionalized by using acid mixture, then this system coated by tin disulfide ( SnS2 ) nanoparticles with nanoparticle sizes controlling. The samples have been characterized by X-Ray diffraction and transmission electron microscopy (TEM). We found size and uniformity of the SnS2 nanoparticles influenced by increasing reaction temperature and time. By increasing reaction temperature and time, size of the SnS2 nanoparticles became larger and nonuniform. Also we found that ultrasound waves could be used instead of organic compounds for avoiding agglomeration of the SnS2 nanoparticles on the surface of MWCNTs.

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