scholarly journals Synthesis of 3D Hollow Structured MnCo2O4/CNTs Nanocomposite and Its Magnetic Properties

2021 ◽  
Author(s):  
Nehad Yousf ◽  
Amir Elzwawy ◽  
Emtinan Ouda ◽  
S. A. Mansour ◽  
El Shazly M. Duraia
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Hollow Structure ◽  
X Ray Diffraction ◽  
Post Heat Treatment ◽  
Present Contribution ◽  
Transmission Electron ◽  
Precipitation Procedure ◽  
Co Precipitation

Abstract In the present contribution, the 3D hollow structure of manganese cobalt oxide/carbon nanotubes (MnCo2O4/CNTs) nanocomposite was successfully synthesized through a co-precipitation procedure followed by post-heat treatment. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Based on the obtained results, the surface of carbon nanotubes was coated uniformly in radial directions by manganese oxide (MnO2) nanosheets forming a flower-shaped structure. In the next step, cobalt oxide precursor was introduced to form MnCo2O4/CNTs nanocomposite. The XRD data confirms the formation of MnCo2O4/CNTs. The estimated values of the strain and the crystallite size based on the Williamson-Hall (W-H) method are calculated as 5.326×10-4 and 16 nm respectively. The fingerprint area of FTIR suggests the successful incorporation of MnO2 and cobalt oxide onto CNTs’ surfaces. The flower-shaped structure in the nanoscale is verified by the FESEM and TEM devices. Furthermore, the magnetic specifications revealed the paramagnetic with a small ferromagnetic component of the aforementioned MnCo2O4/CNTs nanocomposite.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

scholarly journals Synthesis of Co3O4 Nano Aggregates by Co-precipitation Method and its Catalytic and Fuel Additive Applications

2019 ◽  
Vol 17 (1) ◽  
pp. 865-873 ◽  
Author(s):  
Muhammad Ramzan Saeed Ashraf Janjua
Keyword(s):  
Electron Microscopy ◽  
Precipitation Method ◽  
Fuel Additive ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
Calcination Process ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Individual Particles

AbstractThe nano aggregates of cobalt oxide (Co3O4) are synthesized successfully by adopting simple a co precipitation approach. The product obtained was further subjected to the calcination process that not only changed it morphology but also reduces the size of individual particles of aggregates. The prepared nano aggregates are subjected to different characterization techniques such as electron microscopies (scanning electron microscopy and transmission electron microscopy) and X-ray diffraction and results obtained by these instruments are analyzed by different software. The characterization results show that, although the arrangement of particles is compact, several intrinsic spaces and small holes/ pores can also be seen in any aggregate of the product. The as synthesized product is further tested for catalytic properties in thermal decomposition of ammonium perchlorate and proved to be an efficient catalyst.

Efficient synthesis of carbon nanotubes with improved surface area by low-temperature solvothermal route from dichlorobenzene

2013 ◽  
Vol 67 (11) ◽  
Author(s):  
Gantigaiah Krishnamurthy ◽  
Sarika Agarwal
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Source ◽  
Surface Area ◽  
Heating Temperature ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractThe synthesis of well-aggregated carbon nanotubes in the form of bundles was achieved by the catalytic reduction of 1,2-dichlorobenzene by a solvothermal approach. The use of 1,2-dichlorobenzene as a carbon source yielded a comparably good percentage of carbon nanotubes in the range of 60–70 %, at a low reaction temperature of 200°C. The products obtained were analysed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The X-ray diffraction studies implied the presence of pure, crystalline, and well-ordered carbon nanotubes. The scanning electron and transmission electron microscopic images revealed the surface morphology, dimensions and the bundled form of the tubes. These micrographs showed the presence of multi-walled carbon nanotubes with an outer diameter of 30–55 nm, inner diameter of 15–30 nm, and lengths of several hundreds of nanometers. Brunauer-Emmett-Teller-based N2 gas adsorption studies were performed to determine the surface area and pore volume of the carbon nanotubes. These carbon nanotubes exhibit a better surface area of 385.30 m2 g−1. In addition, the effects of heating temperature, heating time, amount of catalyst and amount of carbon source on the product yield were investigated.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

Synthesis of (Y,Gd)2O3:Eu nanopowder by a novel co-precipitation processing

2004 ◽  
Vol 19 (12) ◽  
pp. 3586-3591 ◽  
Author(s):  
Jiyang Chen ◽  
Ying Shi ◽  
Jianlin Shi
Keyword(s):  
Electron Microscopy ◽  
Ammonium Hydroxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen ◽  
Intense Luminescence ◽  
Co Precipitation

Nano-sized (Y,Gd)2O3:Eu powders were synthesized by a novel co-precipitation processing in which a mixture of ammonium hydroxide and ammonium hydrogen carbonate was adopted as a complex precipitant. Evolution behaviors of precursors during calcinations were studied by means of thermogravimetry-differential scanning calorimetry-mass spectrum, Fourier transform infrared, x-ray diffraction, scanning electron microscopy, and transmission electron microscopy in detail. Nano-sized (Y,Gd)2O3:Eu powder as prepared possessed a primary grain size of about 30 nm and specific surface area of 38 m2/g after being calcined at 850 °C for 2 h, showing much finer grains and less agglomeration. The as prepared nanopowder shows intense luminescence at 611nm under x-ray or ultraviolet excitation. Transparent (Y,Gd)2O3:Eu ceramics can also be fabricated using this high sinterable nanopowder.

scholarly journals Investigation on Variables Contributing to the Synthesis of C-S-H/PCE Nanocomposites by Co-Precipitation Method

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7673
Author(s):  
Ziyang You ◽  
Jing Xu
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Orthogonal Experimental Design ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ultra Fine Particle ◽  
Early Performance ◽  
Co Precipitation

The usage of nanoscale calcium silicate hydrate (nano C-S-H) proved to have an excellent promotion effect on the early performance of concrete as nano C-S-H with ultra-fine particle size can act as seeding for cement hydration. Therefore, it is of importance to tune the particle size during the synthesis process of nano C-S-H. In this paper, the influence of several variables of the particle size distribution (PSD) of nano C-S-H synthesized by chemical co-precipitation method with the aid of polycarboxylate (PCE) was studied by orthogonal experimental design. In addition, the composition, microstructure, and morphology of the C-S-H/PCE nanocomposites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum. The results showed that the concentration of reactants had a significant impact on the PSD of C-S-H/PCE nanocomposites, followed by the dosage of dispersant. Ultrasonic treatment was effective in breaking the C-S-H/PCE aggregates with unstable agglomeration structures. The change in synthetic variables had a negligible effect on the composition of the C-S-H/PCE nanocomposites but had a significant influence on the crystallinity and morphology of the composites.

Phosphors for Various Dosimetry Applications Derived by Different Synthesis Routes

2018 ◽  
pp. 53-84
Author(s):  
Jyoti Singh ◽  
Mahesh S. Bhadane ◽  
Vikas Dubey ◽  
Sanjay Daga Dhole ◽  
Jairam Manam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Large Scale ◽  
Scale Production ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Large Scale Production ◽  
Wide Range ◽  
Co Precipitation ◽  
Dose Responses ◽  
Microscopy Techniques

The chapter provides useful information about synthesis and characterization of dysprosium doped oxide and fluoride-based phosphors such as SrGd2O4, CaSO4, and CaF2. Various techniques (e.g., acid-recrystallization, chemical co-precipitation, and homogenous precipitation cum auto-combustion methods) were adopted to synthesize these phosphors for large-scale production. All the prepared phosphors were characterized by x-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy techniques. The thermoluminescence (TL) studies were performed after different irradiation sources such as gamma rays, thermal neutrons, and low energy ions (H, Ar, and N), respectively. Linear dose responses were observed in a wide range of doses for all the samples. Various trapping parameters, namely order of kinetics, activation energy, and frequency factors, were calculated by using computerized glow curve deconvolution (CGCD) method.

Synthesis and Luminescence Properties of Yb3+/Ho3+ Co-Doped Lu2O3 Nanocrystalline Powders

2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Nanocrystalline Powders ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Co Doped

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.

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.

PREPARATION AND CHARACTERIZATION OF A POLY(PYRROLYL METHANE)/MULTIWALLED CARBON NANOTUBES COMPOSITES

NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350063
Author(s):  
JINXIAN LIN ◽  
PAN WANG ◽  
YUYING ZHENG
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Electrode System ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Transfer Resistance ◽  
Transmission Electron

A poly(pyrrolyl methane) (Poly[pyrrole-2, 5-diyl(4-methoxybenzylidane)], PPDMOBA)/multiwalled carbon nanotubes (MWNTs) composites are fabricated by in situ chemical polycondensation of pyrrole and 4-methoxybenzaldehyde on MWNTs. The structure, morphology, thermal stability and electrical property of the resulting composites are investigated via fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and a four-probe method. The electrochemical performance of the composites is determined in a three-electrode system using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. FTIR, FESEM and TEM confirm that the composites have been successfully prepared, and PPDMOBA is uniformly dispersed in MWNTs. Electrical conductivity of PPDMOBA/MWNTs composites is 1.39 S cm-1, which is significantly larger than that of pristine PPDMOBA. The specific capacitance and charge transfer resistance of the composites is 56 F g-1 (1 mA cm-2) and 0.3Ω, respectively.

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