Green synthesis and characterization of ANbO3 (A = Na, K) nanopowders fabricated using a biopolymer

2017 ◽  
Vol 31 (27) ◽  
pp. 1750194
Author(s):  
Gh. H. Khorrami ◽  
M. Mousavi ◽  
S. A. Khayatian ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Green Synthesis ◽  
Average Particle Size ◽  
Synthesis Process ◽  
Bandgap Energy ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Optical Bandgap Energy ◽  
Scherrer Formula

Lead-free sodium niobate (NaNbO3, NN) and potassium niobate (KNbO3, KN) nanopowders were successfully synthesized by a simple and green synthesis process in gelatin media. Gelatin, which is a biopolymer, was used as stabilizer. In order to determine the lowest calcination temperature needed to obtain pure NN and KN nanopowders, the produced gels were analyzed by thermogravometric analyzer (TGA). The produced gels were calcined at 500[Formula: see text]C and 600[Formula: see text]C. The structural and optical properties of the prepared powders were examined using X-ray diffraction (XRD) technique, transmission electron microscopy (TEM), and UV–Vis spectroscopy. The XRD results revealed that pure phase NN and KN nanopowders were formed at low temperature calcination of 500[Formula: see text]C and 600[Formula: see text]C, respectively. The Scherrer formula and size-strain plot (SSP) method were employed to estimate crystallite size and lattice strain of the samples. The TEM images show that the NN and KN samples calcined at 600[Formula: see text]C have cubic shape with an average particle size of 60.95 and 39.29 nm, respectively. The optical bandgap energy of the samples was calculated using UV–Vis diffused reflectance spectra of the samples and Kubelka–Munck relation.

scholarly journals PREPARATION AND STUDY OF FERRITE GARNET R3Fe5O12 (R=Y, Gd, Dy) NANOPARTICLES

2012 ◽  
Vol 15 (2) ◽  
pp. 27-34
Author(s):  
Nguyet Thi Thuy Dao ◽  
Duong Phuc Nguyen ◽  
Hien Duc Than
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Average Particle Size ◽  
Particle Morphology ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Ferrite Garnet ◽  
Transmission Electron ◽  
Scherrer Formula

This paper presents the synthesis and characterization of Y3Fe5O12, Gd3Fe5O12 and Dy3Fe5O12 nanoparticles by sol-gel method using initial salts solution of Y(NO3)3, Gd(NO3)3, Dy(NO3)3, Fe(NO3). The lattice constant, crystallite size and particle morphology of these ferrite garnet nanoparticles were studied by using X-ray diffraction and transmission electron microscopy (TEM). The results showed that the garnet samples prepared by this method were formed at 800oC, which is lower than the sintering temperature for ceramic bulk samples (1400oC). The particle size is in the range 25- 40 nm as observed via TEM image and the average particle size was found to be 37nm using Debye- Scherrer formula.

scholarly journals Structural, Optical, and Compactness Characteristics of NanocrystallineCaNb2O6Synthesized through an Autoigniting Combustion Method

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
K. C. Mathai ◽  
S. Vidya ◽  
Annamma John ◽  
Sam Solomon ◽  
J. K. Thomas
Keyword(s):  
Electron Microscopy ◽  
Average Particle Size ◽  
Combustion Method ◽  
Average Particle ◽  
Sintered Pellet ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Dielectric Constant And Loss ◽  
Scherrer Formula ◽  
Photoluminescence Studies

Nanoparticles of calcium metaniobate compound are prepared by an autoigniting combustion technique and its structural, optical, and dielectric properties are investigated. The X-ray diffraction, Fourier-transform Raman, and infrared studies reveal that calcium metaniobate possesses phase pure orthorhombic columbite structure with space group of Pbcn. The average particle size of the as-prepared nanoparticles obtained from both the Scherrer formula and transmission electron microscopy is ~37 nm. The optical band gap calculated from Tauc's Plot is 3.25 eV. Photoluminescence studies reveal that Calcium metaniobate can be used as an idealphotoluminarmaterial. The powders are pelletised and sintered at an optimized temperature of1350∘Cin a short duration of two hours, yielding a high density. The morphology of the sintered pellet is further examined using scanning electron microscopy. The dielectric constant and loss factor values measured at 5 MHz for a well-sintered Calcium metaniobate pellet are found to be 27.6 and5.3×10−4respectively, at room temperature.

scholarly journals Green synthesis: Proposed mechanism and factors influencing the synthesis of platinum nanoparticles

2020 ◽  
Vol 9 (1) ◽  
pp. 386-398 ◽  
Author(s):  
Mahmood S. Jameel ◽  
Azlan Abdul Aziz ◽  
Mohammed Ali Dheyab
Keyword(s):  
Green Synthesis ◽  
Reaction Temperature ◽  
Platinum Nanoparticles ◽  
Energy Requirement ◽  
Average Particle Size ◽  
High Energy ◽  
Energy Utilization ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Average Particle

AbstractPlatinum nanoparticles (Pt NPs) have attracted interest in catalysis and biomedical applications due to their unique structural, optical, and catalytic properties. However, the conventional synthesis of Pt NPs using the chemical and physical methods is constrained by the use of harmful and costly chemicals, intricate preparation requirement, and high energy utilization. Hence, this review emphasizes on the green synthesis of Pt NPs using plant extracts as an alternative approach due to its simplicity, convenience, inexpensiveness, easy scalability, low energy requirement, environmental friendliness, and minimum usage of hazardous materials and maximized efficiency of the synthesis process. The underlying complex processes that cover the green synthesis (biosynthesis) of Pt NPs were reviewed. This review affirms the effects of different critical parameters (pH, reaction temperature, reaction time, and biomass dosage) on the size and shape of the synthesized Pt NPs. For instance, the average particle size of Pt NPs was reported to decrease with increasing pH, reaction temperature, and concentration of plant extract.

Preparation and Magnetic Properties of Carbon Encapsulated Fe-Cu Alloy Nanoparticles

2010 ◽  
Vol 177 ◽  
pp. 673-676 ◽  
Author(s):  
Jun Xue ◽  
Hou Kui Xiang ◽  
Hong Qiao Ding ◽  
Shu Li Pang ◽  
Xue Hua Wang ◽  
...  
Keyword(s):  
Magnetic Measurement ◽  
Average Particle Size ◽  
Soft Magnetic Property ◽  
Copper Nitrate ◽  
Synthesis Process ◽  
Ferric Nitrate ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Alloy

Carbon encapsulated Fe-Cu alloys nanoparticles were synthesized by using ferric nitrate, copper nitrate as metal sources and using sucrose as carbon source. The synthesis process involved a step of hydrazine hydrate reduction in alcohol solution and a step of annealing carbonization. The as-prepared samples were characterized by X-ray diffraction technique, X-ray energy dispersion spectrograph, trans- mission electron microscopy and Raman spectroscopy. The results showed the sample was core / shell structure, the metalic core was crystalline FeCu4 alloy, the shell was amorphous carbon, and the average particle size was about 51nm. The magnetic measurement by using a vibrating sample magnetometer revealed that the sample has ultra-soft magnetic property with the saturation magnetization Ms of 13.01 emu/g, residual magnetization Mr of 0.37 emu/g and coercive forces Hc of 54.43 Oe at room temperature.

scholarly journals Fe2O3 Modified Physical, Structural and Optical Properties of Bismuth Silicate Glasses

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Rajesh Parmar ◽  
R. S. Kundu ◽  
R. Punia ◽  
N. Kishore ◽  
P. Aghamkar
Keyword(s):  
Optical Properties ◽  
Silicate Glasses ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Scanning Calorimetry ◽  
Bismuth Silicate ◽  
Vis Spectroscopy ◽  
Amorphous Nature ◽  
Optical Bandgap Energy

Iron-containing bismuth silicate glasses with compositions 60SiO2·(100−x)Bi2O3·xFe2O3 have been prepared by conventional melt-quenching technique. The amorphous nature of the glass samples has been ascertained by the X-ray diffraction. The density (d) has been measured using Archimedes principle, molar volume (Vm) has also been estimated, and both are observed to decrease with the increase in iron content. The glass transition temperature (Tg) of these iron bismuth silicate glasses has been determined using differential scanning calorimetry (DSC) technique, and it increases with the increase in Fe2O3 content. The IR spectra of these glasses consist mainly of [BiO6], [BiO3], and [SiO4] structural units. The optical properties are measured using UV-VIS spectroscopy. The optical bandgap energy (Eop) is observed to decrease with the increase in Fe2O3 content, whereas reverse trend is observed for refractive index.

scholarly journals Green Synthesis of Novel Jasmine Bud-Shaped Copper Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Malathi Sampath ◽  
Ramya Vijayan ◽  
Ezhilarasu Tamilarasu ◽  
Abiraman Tamilselvan ◽  
Balasubramanian Sengottuvelan
Keyword(s):  
Copper Nanoparticles ◽  
Isonicotinic Acid ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Acid Hydrazide ◽  
Reducing Agent ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron

Novel jasmine bud-shaped copper nanoparticles were synthesized by a green chemical reduction method using polyvinylpyrrolidone (PVP) as a capping agent, L-ascorbic acid (AA) as a reducing agent as well as antioxidant agent, isonicotinic acid hydrazide (INH) as a reducing agent, and water as a solvent at 60–70°C (pH-7) in the presence of air. The UV-Vis absorption maximum obtained is 573 nm. The crystal lattice (fcc) structure of Cu Nps was confirmed by X-ray diffraction (XRD). The novel jasmine bud shape was visualized in a transmission electron microscope (TEM). The height of single copper nanobud was 6.41 nm as measured by atomic force microscope (AFM). The average particle size 6.95 nm is obtained by XRD results. Antibacterial activity of the Cu nanobuds was evaluated by testing against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

DIELECTRIC PROPERTIES OF ULTRAFINE Zn-DOPED CaCu3Ti4O12 CERAMIC

2012 ◽  
Vol 02 (01) ◽  
pp. 1250007 ◽  
Author(s):  
LAXMAN SINGH ◽  
U. S. RAI ◽  
K. D. MANDAL ◽  
MADHU YASHPAL
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sintered Powder

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.

Frequency dependence and fuel effect on optical properties of nano TiO2-based structures

2016 ◽  
Vol 30 (18) ◽  
pp. 1650247 ◽  
Author(s):  
Mahdi Ghasemifard ◽  
Misagh Ghamari ◽  
Meysam Iziy
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Average Particle Size ◽  
Combustion Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Transmission Electron ◽  
Auto Combustion ◽  
Xrd Patterns

TiO2-(Ti[Formula: see text]Si[Formula: see text]O2 nanopowders (TS-NPs) with average particle size around 90 nm were successfully synthesized by controlled auto-combustion method by using citric acid/nitric acid (AC:NA) and urea/metal cation (U:MC). The structure of powders was studied based on their X-ray diffraction (XRD) patterns. The XRD of TS-NPs shows that rutile and anatase are the main phases of TS-NPs for AC:NA and U:MC, respectively. Particle size and histogram of nanopowders were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Optical properties of TS-NPs were calculated by Fourier transform infrared spectroscopy (FTIR) and Kramers–Kroning (KK) relation. Plasma frequencies of TS-NPs obtained from energy loss functions depend on fuels as a result of changes in crystal structure, particle size distribution, and morphology.

scholarly journals Magnetic and Structural Studies of CoFe2O4Nanoparticles Suspended in an Organic Liquid

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Branka Babić-Stojić ◽  
Vukoman Jokanović ◽  
Dušan Milivojević ◽  
Zvonko Jagličić ◽  
Darko Makovec ◽  
...  
Keyword(s):  
Room Temperature ◽  
Bulk Material ◽  
Organic Liquid ◽  
Average Particle Size ◽  
Hydrodynamic Diameter ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ferrite Nanoparticle ◽  
Nanoparticle System

We present a study of magnetic and structural properties of CoFe2O4nanoparticles suspended in an organic liquid. Transmission electron microscopy shows that the nanoparticles have a narrow size distribution of average particle size 5.9 ± 1.0 nm. X-ray diffraction shows that the particles are of cubic spinel crystal structure. Dynamic light scattering measurements reveal the existence of an organic shell around the CoFe2O4nanoparticles with an average hydrodynamic diameter of 14.4 nm. Coercive magnetic field atT=5 K is found to be 11.8 kOe. Disappearance of the coercive field and remanent magnetization at about 170 K suggests that the CoFe2O4nanoparticles are superparamagnetic at higher temperatures which is confirmed by the room temperature Mössbauer spectrum analysis. Saturation magnetization of the nanoparticles of 80.8 emu/g(CoFe2O4) at 5 K reaches the value detected in the bulk material and remains very high also at room temperature. The cobalt ferrite nanoparticle system synthesized in this work exhibits magnetic properties which are very suitable for various biomedical applications.

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