scholarly journals Synthesis and electrochemical properties of LaMnO3 orthosized nanomaterial for supercapacitor applications

2020 ◽  
Vol 21 (2) ◽  
pp. 219-226
Author(s):  
B. K. Ostafiychuk ◽  
H. M. Kolkovska ◽  
I. P. Yaremiy ◽  
B. I. Rachiy ◽  
P. I. Kolkovskyi ◽  
...  

In this work, the perovskite LaMnO3 material has been prepared based on the sol-gel process of synthesis with the participation of combustion. According to the X-ray phase analysis, it was determined that the obtained material consists of LaMnO3 one phase (space group Pm-3m). Nevertheless, it has been determined that the average size of the coherent scattering region of the obtained material is about 24 nm. Moreover, the average particle size is 40-60 nm in case the approximation that the particles are spherical shape. Thus, it has been determined that the specific surface area of the material is 42.1 m2/g. The electrochemical investigations have been performed using nanosized LaMnO3 powder as a cathode material for electrochemical capacitors. The LaMnO3 material under research showed a specific capacity of 40 F/g at a discharge of up to 1V.

2010 ◽  
Vol 8 (5) ◽  
pp. 1041-1046 ◽  
Author(s):  
Raúl Reza ◽  
Carlos Martínez Pérez ◽  
Claudia Rodríguez González ◽  
Humberto Romero ◽  
Perla García Casillas

AbstractIn this work, the synthesis of magnetite nanoparticles by two variant chemical coprecipitation methods that involve reflux and aging conditions was investigated. The influence of the synthesis conditions on particle size, morphology, magnetic properties and protein adsorption were studied. The synthesized magnetite nanoparticles showed a spherical shape with an average particle size directly influenced by the synthesis technique. Particles of average size 27 nm and 200 nm were obtained. When the coprecipitation method was used without reflux and aging, the smallest particles were obtained. Magnetite nanoparticles obtained from both methods exhibited a superparamagnetic behavior and their saturation magnetization was particle size dependent. Values of 67 and 78 emu g−1 were obtained for the 27 nm and 200 nm magnetite particles, respectively. The nanoparticles were coated with silica, aminosilane, and silica-aminosilane shell. The influence of the coating on protein absorption was studied using Bovine Serum Albumin (BSA) protein.


2018 ◽  
Vol 762 ◽  
pp. 408-412
Author(s):  
Raivis Eglītis ◽  
Gundars Mežinskis

In this work two different hydrosols were used to impregnate a commercially available cotton fabric with anatase nanoparticles to give it photocatalytic activity. To increase the activity, different pre-treatment methods were applied. The nanoparticle size was determined using dynamic light scattering and x-ray diffraction and the fabrics were examined using scanning electron microscopy. Photocatalytic activity was measured using the degradation of methyl-orange while irradiating the samples with UV light. The synthesis method allowed to produce anatase with an average particle size of 32 to 37 nm depending on the synthesis method used.


2011 ◽  
Vol 412 ◽  
pp. 271-274
Author(s):  
Ying Li ◽  
Qiang Xu ◽  
Ling Dai

In order to prepare ultrafine La3NbO7 powder, a potential material for thermal barrier coatings, the calcination process of La3NbO7 was studied in this paper.The precursor of La3NbO7 was synthesized by using a citric acid complex method. A calcination process had been systematically investigated. The reaction temperature was determined by differential scanning calorimetry (DSC). The phase composition of powders was characterized by X-ray diffraction (XRD), and the morphology was obtained by scanning electron microscope (SEM). The results revealed that the single-phase La3NbO7 powder could be successfully prepared while the calcination temperature exceeded 800°C and a better morphology could be maintained at 800°C for 4 hours. Considering all above, an optimum calcination scheme was adopted at 800°C for 4 hours. The as-prepared La3NbO7 powders had a grain size of about 50nm and an average particle size of about 300nm.


2016 ◽  
Vol 16 (4) ◽  
pp. 3914-3920 ◽  
Author(s):  
G. Z Li ◽  
F. H Liu ◽  
Z. S Chu ◽  
D. M Wu ◽  
L. B Yang ◽  
...  

SiO2@Y2MoO6:Eu3+ core–shell phosphors were prepared by the sol–gel process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as kinetic decays were used to characterize the resulting SiO2@Y2MoO6:Eu3+ core–shell phosphors. The XRD results demonstrated that the Y2MoO6:Eu3+ layers on the SiO2 spheres crystallized after being annealed at 700 °C and the crystallinity increased with raising the annealing temperature. The obtained core–shell phosphors have spherical shape with narrow size distribution (average size ca. 640 nm), non-agglomeration, and smooth surface. The thickness of the Y2MoO6:Eu3+ shells on the SiO2 cores could be easily tailored by varying the number of deposition cycles (70 nm for four deposition cycles). The Eu3+ shows a strong PL emission (dominated by 5D0–7F2 red emission at 614 nm) under the excitation of 347 nm UV light. The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.


2011 ◽  
Vol 287-290 ◽  
pp. 1731-1734 ◽  
Author(s):  
Han Sheng Li ◽  
Hang Xu ◽  
Shi Ying Wang ◽  
Ya Lin Pan ◽  
Qin Wu ◽  
...  

Anatase nano-titania (nano-TiO2) was prepared by using a sol-gel process mediated in reverse microemulsion combined with a solvent thermal technique. The results show that the anatase structure appears in the calcination temperature range of 400-510°C, while the transformation of anatase into rutile takes place above 510°C. The average particle size (dP) of the nano-TiO2 increases with the rise of water/Triton X-100 molar ratio (ω) but decreases with the rise of acetyl acetone/n-TBT molar ratio (p) and n-hexanol/Triton X-100 molar ratio (m). The obtained TiO2 particles with a small size have high photocatalytic activity.


2020 ◽  
Vol 11 (1) ◽  
pp. 747-754
Author(s):  
Saja S. Al-Taweel ◽  
Rana S. Al-Taweel ◽  
Hasan M. Luaibi

In this work, zinc oxide nanoparticles (ZnO - NPs) were prepared using a sol-gel methodology and tested for their antibacterial activity against each of the following pathogenic species: Escherichia coli, Klebsiella pneumonia, and Staphylococcus aureus by well diffusion assay. The sample prepared was characterized by different techniques: Atomic Force Microscope AFM; Fourier Transform Infrared FT-IR; Scanning Electron Microscope SEM and X-Ray Diffraction Spectroscopy XRD. The XRD result showed that ZnO - NPs presence in wurtzite the structure of ZnO. The AFM and SEM of the surface analysis indicate that the most ZnO – NPs appear approximately in a spherical shape with some agglomeration. The average particle size for  ZnO - NPs is nearly 37 nm. Volumes 25µl, 50µl, 75µl, 100µl, 125µl, and 150µl of 10 mg\ ml concentration of  ZnO - NPs were used, the antimicrobial activity results showed that ability for  ZnO - NPs to inhibit the growth of S.aureus increased as the solution volume increased, while the growing of (K. pneumonia) and (E. coli) was inhibited only with the volume 75µl where the inhibition zones diameters were 15mm and 10mm respectively.


2021 ◽  
Vol 10 (1) ◽  
pp. 74-78
Author(s):  
Nhan Dang Thi Thanh ◽  
Don Truong Thi ◽  
Thang Le Quoc ◽  
Tien Tran Dong ◽  
Son Le Lam

Presently, biopolymer materials have been given more attention for their outstanding properties, high efficiencies and promising applications in various fields. In this study, Fe2O3/chitosan aerogel-like spheres were successfully prepared from chitosan and FeCl3 by sol–gel process and freeze-drying to provide high-surface area materials. The factors affecting the material synthesis have been studied. The asprepared Fe2O3/chitosan material was characterized by Infrared Spectroscopy (IR), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) methods. The results showed that the aerogel spheres have a hollow structure made of chitosan nanofibril networks. Fe2O3 nanoparticles get high crystallinity and have an average particle size of 33 nm.


2010 ◽  
Vol 7 (3) ◽  
pp. 894-898 ◽  
Author(s):  
T. V. Anuradha

Nanocrystalline perovskite barium titanate with an average particle size less than ∼10 nm is produced using sol-gel route involving ligand-assisted templating. BaTiO3is obtained by the controlled hydrolysis and condensation reaction of barium acetate (Ba(CH3COO)2) with titanium tetra chloride (TiCl4) in the reverse micelles of dodecylamine (DDA) which is used as the template. Our attempts to produce mesoporous BaTiO3have resulted in the formation of nanocrystalline BaTiO3. The synthesis of nanostructured BaTiO3is carried out using the ligand-assisted templating approach which proceeds through the sol-gel route. Dodecylamine is used as the template. The sol-gel process in general presents inherent advantages because the nanostructure of the desired materials can be controlled together with their porous structure. Ligand-assisted templating approach involves the formation of covalent bond between the inorganic analogue and the template. Ba(CH3COO)2and TiCl4are used as barium-source and titanium-source respectively. The reaction between Ba(CH3COO)2and TiCl4is found to take place deliberately on the pre-assembled species which acts as the template or occurring with in them which in turn will lead to the generation of the desired nanoscale structure (nanopores or nanoparticles).


2009 ◽  
Vol 151 ◽  
pp. 113-117 ◽  
Author(s):  
Lyudmil V. Todorov ◽  
Carla I. Martins ◽  
Júlio C. Viana

This study investigates the influence of various nanofillers of different shapes and sizes on the properties of PET nanocomposites. PET was reinforced with 0.3 wt.% of different nanoreinforcements, namely: (i) 1D platelet-like shape of organo-modified layered silicates (montmorillonite) (platelet size approx. 1 x 200 nm) with average agglomerate size of: (a) 30 μm and (b) 8 μm; (ii) 3D spherical shape particles of titanium oxide with an average size of 21 nm and (iii) 3D spherical shape silica with an average particle size of 12 nm. PET nanocomposites were prepared by melt blending in an asymmetric batch minimixer followed by compression moulding process. The effect of nanofillers upon thermal, mechanical and structural properties in comparison to the neat PET are discussed.


2017 ◽  
Vol 18 (4) ◽  
pp. 444-448
Author(s):  
I. P. Yaremiy ◽  
M. L. Mokhnatskyi ◽  
L. V. Mokhnatska ◽  
S. I. Yaremiy ◽  
A. I. Kachmar

Nanoscale powders of LaFe0.5Cr0.5O3 with perovskite structure were synthesized by the sol-gel combustion method in this work. From X-rays phase analysis obtained material consisted of one phase LaFe0.5Cr0.5O3 (space group P m -3 m). The average size of RCS of test material is 21 nm. The specific surface area is 14 m2/g. The average particle size is 63.7 nm by approximation that particles form is spherical. Nanoscale powders of LaFe0.5Cr0.5O3were tested as cathode material for lithium power sources. The cathode material demonstrates the specific power capacity of 571 A•h/kg when the discharge of the source is up to 0.5V.


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