scholarly journals Nickel-Doped Cerium Oxide Nanoparticles: Green Synthesis Using Stevia and Protective Effect against Harmful Ultraviolet Rays

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4424 ◽  
Author(s):  
Mehrdad Khatami ◽  
Mina Sarani ◽  
Faride Mosazadeh ◽  
Mohammadreza Rajabalipour ◽  
Alireza Izadi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cerium Oxide ◽  
Field Emission ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Ni Doping ◽  
X Ray ◽  
Scanning Electron

Nanoparticles of cerium oxide CeO2 are important nanomaterials with remarkable properties for use in both industrial and non-industrial fields. In a general way, doping of oxide nanometric with transition metals improves the properties of nanoparticles. In this study, nickel- doped cerium oxide nanoparticles were synthesized from Stevia rebaudiana extract. Both doped and non-doped nanoparticles were characterized by X-ray diffraction, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray, Raman spectroscopy, and Vibrating-Sample Magnetometry analysis. According to X-ray diffraction, Raman and Energy Dispersive X-ray crystalline and single phase of CeO2 and Ni doped CeO2 nanoparticles exhibiting fluorite structure with F2g mode were synthesized. Field Emission Scanning Electron Microscopy shows that CeO2 and Ni doped nanoparticles have spherical shape and sizes ranging of 8 to 10 nm. Ni doping of CeO2 results in an increasing of magnetic properties. The enhancement of ultraviolet protector character via Ni doping of CeO2 is also discussed.

scholarly journals Cerium Oxide Nanoparticles: Synthesis and Characterization for Biosafe Applications

2021 ◽  
Vol 1 (3) ◽  
pp. 176-189
Author(s):  
Prathima Prabhu Tumkur ◽  
Nithin Krisshna Gunasekaran ◽  
Babu R. Lamani ◽  
Nicole Nazario Bayon ◽  
Krishnan Prabhakaran ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cerium Oxide ◽  
Ceo2 Nanoparticles ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diphenyltetrazolium Bromide ◽  
Scanning Electron

Due to its excellent physicochemical properties, cerium oxide (CeO2) has attracted much attention in recent years. CeO2 nanomaterials (nanoceria) are widely being used, which has resulted in them getting released to the environment, and exposure to humans (mostly via inhalation) is a major concern. In the present study, CeO2 nanoparticles were synthesized by hydroxide-mediated method and were further characterized by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction Spectroscopy (XRD). Human lung epithelial (Beas-2B) cells were used to assess the cytotoxicity and biocompatibility activity of CeO2 nanoparticles. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and Live/Dead assays were performed to determine the cytotoxicity and biocompatibility of CeO2 nanoparticles. Generation of reactive oxygen species (ROS) by cerium oxide nanoparticles was assessed by ROS assay. MTT assay and Live/Dead assays showed no significant induction of cell death even at higher concentrations (100 μg per 100 μL) upon exposure to Beas-2B cells. ROS assay revealed that CeO2 nanoparticles did not induce ROS that contribute to the oxidative stress and inflammation leading to various disease conditions. Thus, CeO2 nanoparticles could be used in various applications including biosensors, cancer therapy, catalytic converters, sunscreen, and drug delivery.

scholarly journals Synthesis, Characterization, and Antimicrobial Activity of CoO Nanoparticles from a Co (II) Complex Derived from Polyvinyl Alcohol and Aminobenzoic Acid Derivative

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Maged S. Al-Fakeh ◽  
Roaa O. Alsaedi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cobalt Oxide ◽  
Oxide Nanoparticles ◽  
Aminobenzoic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cobalt Oxide Nanoparticles ◽  
Coo Nanoparticles ◽  
Scanning Electron

Cobalt oxide nanoparticles (CoO NPs) were synthesized by the calcination method from the Co (II) complex which has the formula [Co(PVA)(P-ABA)(H2O)3], PVA = polyvinyl alcohol, and P-ABA = para-aminobenzoic acid. The calcination temperature was 550°C, and the products were characterized by element analysis, thermal analyses (TGA and DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-Vis spectra, and scanning electron microscopy (SEM) techniques. The kinetic and thermodynamic parameters (∆H   ∗ , ∆G   ∗ , and ∆S   ∗ ) for the cobalt (II) complex are calculated. The charges been carried by the atoms cause dipole moment 10.53 and 3.84 debye and total energy 11.04 × 102 and 24.80 × 102k Cal mol−1 for the Co (II) complex and cobalt oxide, respectively. X-ray diffraction confirmed that the resulting oxide was pure single-crystalline CoO nanoparticles. Scanning electron microscopy indicating that the crystallite size of cobalt oxide nanocrystals was in the range of 36–54 nm. Finally, the antimicrobial activity of cobalt oxide nanoparticles was evaluated using four bacterial strains and one fungal strain. Two strains of Gram-positive cocci (Staphylococcus aureus and Enterococcus faecalis), two strains of Gram-negative bacilli (Escherichia coli and Pseudomonas aeruginosa), and one strain of yeast such as fungi (Candida albicans) were used in this study.

Nanostructured CaWO4, CaWO4:Eu3+ and CaWO4:Tb3+ Particles: Sonochemical Synthesis and Luminescent Properties

2008 ◽  
Vol 8 (3) ◽  
pp. 1183-1190 ◽  
Author(s):  
Chunxia Li ◽  
Cuikun Lin ◽  
Xiaoming Liu ◽  
Jun Lin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Field Emission ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Blue Emission Band ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Nanostructured CaWO4, CaWO4:Eu3+, and CaWO4:Tb3+ phosphor particles were synthesized via a facile sonochemical route. X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, low voltage cathodoluminescence spectra, and photoluminescence lifetimes were used to characterize the as-obtained samples. The X-ray diffraction results indicate that the samples are well crystallized with the scheelite structure of CaWO4. The transmission electron microscopy and field emission scanning electron microscopy images illustrate that the powders consist of spherical particles with sizes from 120 to 160 nm, which are the aggregates of even smaller nanoparticles ranging from 10 to 20 nm. Under UV light or electron beam excitation, the CaWO4 powder exhibited a blue emission band with a maximum at 430 nm originating from the WO2−4 groups, while the CaWO4:Eu3+ powder showed red emission dominated by 613 nm ascribed to the 5D0 → 7F2 of Eu3+, and the CaWO4:Tb3+ powders showed emission at 544 nm, ascribed to the 5D4 → 7F5 transition of Tb3+. The PL excitation and emission spectra suggest that the energy is transferred from WO2−4 to Eu3+CaWO4:Eu3+ and to Tb3+ in CaWO4:Tb3+. Moreover, the energy transfer from WO2−4 to Tb3+ in CaWO4:Tb3+ is more efficient than that from WO2−4 to Eu3+ in CaWO4:Eu3+. This novel and efficient pathway could open new opportunities for further investigating the novel properties of tungstate materials.

Synthesis of Zinc Doped-Biphasic Calcium Phosphate Nanopowder via Sol-Gel Method

2012 ◽  
Vol 531-532 ◽  
pp. 614-617 ◽  
Author(s):  
Gunawan ◽  
I. Sopyan ◽  
A. Naqshbandi ◽  
S. Ramesh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Phosphate ◽  
Field Emission ◽  
Biphasic Calcium Phosphate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Scanning Electron

Biphasic calcium phosphate powders doped with zinc (Zn-doped BCP) were synthesized via sol-gel technique. Different concentrations of Zn have been successfully incorporated into biphasic calcium (BCP) phases namely: 1%, 2%, 3%, 5%, 7%, 10% and 15%. The synthesized powders were calcined at temperatures of 700-900°C. The calcined Zn-doped BCP powders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential and thermogravimetric analysis (TG/DTA) and field-emission scanning electron microscopy (FESEM). X-ray diffraction analysis revealed that the phases present in Zn-doped are hydroxyapatite, β- TCP and parascholzite. Moreover, FTIR analysis of the synthesized powders depicted that the bands of HPO4 increased meanwhile O-H decreased with an increase in the calcination temperature. Field emission scanning electron microscopy (FESEM) results showed the agglomeration of particles into microscale aggregates with size of the agglomerates tending to increase with an increase in the dopant concentration.

Adsorption and degradation of Congo red on a jarosite-type compound

RSC Advances ◽  
2016 ◽  
Vol 6 (105) ◽  
pp. 102972-102978 ◽  
Author(s):  
Yu Dong ◽  
Ziting Wang ◽  
Xin Yang ◽  
Meiying Zhu ◽  
Rufen Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Congo Red ◽  
X Ray Diffraction ◽  
X Ray ◽  
Type Compound ◽  
Forced Hydrolysis ◽  
Scanning Electron

Natrojarosite particles were prepared by forced hydrolysis. X-ray diffraction and field-emission scanning electron microscopy were used to characterize the resulting products.

scholarly journals Electrochemical Formation of Cerium Oxide/Layered Silicate Nanocomposite Films

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Adele Qi Wang ◽  
Teresa Diane Golden
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cerium Oxide ◽  
Layered Silicate ◽  
Nanocomposite Films ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Scanning Electron

Cerium oxide/montmorillonite nanocomposite films were synthesized electrochemically from solutions containing 0.5 to 50% Na-montmorillonite. The nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. Nanocomposite films synthesized from montmorillonite concentrations lower than 10% were continuous, uniform, and dense. X-ray diffraction confirmed that the nanocomposite films retain the face-centered cubic structure of cerium oxide while incorporating exfoliated platelets of the montmorillonite into the matrix. In addition, calculations from XRD data showed particle sizes ranging from 4.50 to 6.50 nm for the nanocomposite coatings. Raman and FTIR spectroscopy had peaks present for cerium oxide and the layered silicates in the coatings. Cross-sectional scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed the presence of montmorillonite throughout the cerium oxide matrix.

Hollow Crystals of BiFeO3 Prepared via a Al3+-Assisted Hydrothermal Method

2012 ◽  
Vol 174-177 ◽  
pp. 516-519
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Method ◽  
Field Emission ◽  
Growth Mechanism ◽  
Irregular Shape ◽  
Morphology Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The BiFeO3 hollow crystals were successfully prepared at 200oC by a Al3+assisted hydrothermal method. The structures and morphologies of the as-obtained products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (SEM). A morphology evolution from irregular shape to square, hollow, and sphere-like was observed as the Al ions concentration varied from 0% to 1.5%. The possible growth mechanism of the BiFeO3hollow crystals was also discussed.

Comparative High-Resolution X-Ray Diffraction Analysis of GaN/AlGaN Heterostructure on Al2O3 and Si (111) Substrate Grown by Plasma Assisted Molecular Beam Epitaxy

2015 ◽  
Vol 1754 ◽  
pp. 129-134
Author(s):  
Sanjay Kr. Jana ◽  
Saptarsi Ghosh ◽  
Syed Mukulika Dinara ◽  
Apurba Chakraorty ◽  
D. Biswas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Field Emission ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Scanning Electron

AbstractThe work presents a comparative study on GaN/AlGaN type-II heterostructures grown on c-plane Al2O3 and Si (111) substrates by Plasma Assisted Molecular Beam Epitaxy. The in-depth structural characterizations of these samples were performed by High-Resolution X-Ray Diffraction, X-ray Reflectivity and Field Emission Scanning Electron Microscopy. The in-plane and out-of plane strains were determined from measured c- and a-lattice parameters of the epilayers from reciprocal space mapping of both symmetric triple axis (002) and asymmetric grazing incidence (105) double axis mode. The mosaicity parameters like tilt and correlation lengths were also calculated from reciprocal space mapping. Moreover, the twist angle was measured from skew symmetric off axis scan of (102), (103), and (105) planes along with (002) symmetric plane. The defect density were measured from the full width at half maxima of skew symmetric scan of (002) and (102) reflection planes. Also, the strained states of all the layers were analyzed and corresponding Al mole fraction was calculated based on anisotropic elastic theory. The thicknesses of the layers were measured from simulation of the nominal structure by fitting with X-ray Reflectivity experimental curves and also by comparing with cross sectional Field Emission Scanning Electron Microscopy micrographs.

scholarly journals Heterogeneous Cu–Fe oxide catalysts for preferential CO oxidation (PROX) in H2-rich process streams

RSC Advances ◽  
2020 ◽  
Vol 10 (59) ◽  
pp. 35792-35802
Author(s):  
Venkata D. B. C. Dasireddy ◽  
Krish Bharuth-Ram ◽  
Darko Hanzel ◽  
Blaž Likozar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Monoxide ◽  
Co Oxidation ◽  
Field Emission ◽  
Oxide Catalysts ◽  
X Ray Diffraction ◽  
Preferential Co Oxidation ◽  
X Ray ◽  
Scanning Electron

Fe loading in Cu–Fe phases and its effect on carbon monoxide oxidation in H2-rich reactant streams were investigated with the catalyst material phases characterized by Field Emission Scanning Electron Microscopy, X-ray diffraction studies and Mössbauer Spectroscopy.

Strong Ultra-Violet Absorption in Cu Doped CeO2 Nanospheres

2018 ◽  
Vol 24 (8) ◽  
pp. 5947-5952 ◽  
Author(s):  
M Ponnar ◽  
K Pushpanathan
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Cerium Oxide ◽  
Field Emission ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Doping ◽  
Transmission Electron ◽  
Scanning Electron

This article focuses the synthesis and characterization of copper doped cerium oxide nanospheres synthesized by chemical precipitation method. Synthesized nanopowders were characterized by means of X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, ultraviolet-visible spectrometer and photoluminescence spectrometer. X-ray diffraction study confirmed the copper doping without disturbing the face centred cubic structure of cerium oxide. Field emission scanning electron microscope and transmission electron microscope study also confirmed the existence of sphere like nanoparticles. The optical absorption spectrum shows that the synthesized samples exhibit strong absorption in ultraviolet region and also it confirmed the decrease in energy gap of cerium oxide on copper doping. The photoluminescence study revealed that the blue emission is attributed to the fast oxygen transportation of copper doped cerium oxide nanoparticles.

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