scholarly journals Nb2O5 nanoparticles obtained by microwave assisted combustion synthesis under different conditions

2021 ◽  
Vol 15 (2) ◽  
pp. 128-135
Author(s):  
Thaís Luiz ◽  
Fabio Nakagomi ◽  
Reny Renzetti ◽  
Guilherme Siqueira
Keyword(s):  
Combustion Synthesis ◽  
Diffuse Reflectance Spectroscopy ◽  
Low Cost ◽  
Synthesis Method ◽  
Particle Growth ◽  
Synthesis Temperature ◽  
Band Gap Energy ◽  
Stoichiometric Ratio ◽  
Synthesis Of Nanoparticles ◽  
Microwave Assisted

The microwave assisted combustion synthesis (MACS) as a new, quick and low cost synthesis method was used for preparation of niobium pentoxide (Nb2O5) powders. The present paper investigated the effect of reactant concentrations (ammonium niobium oxalate, urea and ammonium nitrate) on the characteristics of Nb2O5 nanoparticles. Three samples were synthesized with stoichiometric ratio between the fuel and oxidant (C1), excess of oxidant (C2) and excess of fuel (C3). In all samples, Nb2O5 crystalline nanoparticles with irregular morphology were detected. The synthesis of nanoparticles with smaller diameter in the C2 and C3 samples was confirmed by greater values of band gap energy measured through UV-Visible diffuse reflectance spectroscopy (indicating quantum confinement) and by the Rietveld refinement of X-ray diffraction patterns. The results showed that the amounts of oxidant and fuel can change synthesis temperature, influencing the final characteristics of the particles, such as size and existent phases. In these cases the excess of oxidant and fuel in the C2 and C3 samples, respectively, decreases the average synthesis temperature and decelerates the particle growth and the formation of the monoclinic phase.

scholarly journals Structural and Optical Properties of MAl2O4 Spinel-type Prepared by Solution Combustion Synthesis Method for Photocatalytic Application

2021 ◽  
Vol 32 (3) ◽  
pp. 61-73
Author(s):  
Khaled Mahi ◽  
◽  
Rabah Mostefa ◽  
◽  
Keyword(s):  
Optical Properties ◽  
Combustion Synthesis ◽  
Diffuse Reflectance Spectroscopy ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Band Gap Energy ◽  
Solution Combustion ◽  
Spinel Type ◽  
Phase Spinel ◽  
Ft Ir

In this research, the aluminate spinel type materials, MAl2O4, are synthesised by solution combustion synthesis (SCS) method to investigate the effect of the element (M = Ca and Ba) on their structural, mainly crystallinity and optical properties. The characterisations are examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and UV-visible diffuse reflectance spectroscopy (UV-DRS). The XRD and FT-IR results showed the formation of the single-phase spinel structure of CaAl2O4 and BaAl2O4. The band gap energy was investigated using the Tauc method, and the obtained values were 3.93 eV and 3.77 eV for CaAl2O4 and BaAl2O4, respectively. The results showed a good agreement with the data as reported in the literature.

scholarly journals Microwave Assisted-Hydrothermal Synthesis of Nickel Ferrite Nanoparticles

2018 ◽  
Vol 34 (5) ◽  
pp. 2577-2582
Author(s):  
Mohamed H. H. Mahmoud ◽  
Mahmoud M. Hessien
Keyword(s):  
Nickel Ferrite ◽  
High Performance ◽  
Fine Particles ◽  
Low Cost ◽  
Nickel Chloride ◽  
Heating Time ◽  
Stoichiometric Ratio ◽  
Microwave Assisted ◽  
Xrd Patterns ◽  
Co Precipitation

Nanomagnetic ferrite materials are of great technological importance in several industries due to their high performance, ease of preparation and low cost. The ferrite properties are based on composition, structure and methods of preparation. Nickel ferrite, NiFe2O4, was prepared by the simple microwave assisted-hydrothermal method. Nickel chloride and ferric chloride solutions (stoichiometric ratio of 1: 2 respectively) were mixed, the pH was raised to 10.5 and the mixture was heated at 180 °C in a closed Teflon vessel using a microwave oven at different periods of time (2 - 24 h). The formed powders were examined by XRD, TEM, and VSM. The intensity of nickel-ferrite in the XRD patterns increased with time owing to increase in crystallinity of the formed phase. The TEM images showed that, the size was in the range of 20-40 nm and contents of fine particles noticeably decreased with increasing reaction time to 4-6 hrs and contents of more regular cubic particles are formed. The NiFe2O4 magnetization was continuesly increased with raising the heating time from 2h (9 emu/g) to 24 h (43 emu/g) which may be due to the high purity and crystallinity of the formed NiFe2O4. The results showed that the properties of the formed ferrite can be tailored by controlling the heating time. Microwave assisted co-precipitation followed by hydrothermal digestion resulted in a substance of good homogeneity and crystallinity at a short time.

scholarly journals Synthesis and Characterization Titanium Dioxide (TiO2) Doped Vanadium(V) Using Solid State Method

ALCHEMY ◽  
2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Khusnan Mustofa ◽  
Nur Aini ◽  
Susi Nurul Khalifah
Keyword(s):  
Titanium Dioxide ◽  
Solid State ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Synthesis Method ◽  
Band Gap Energy ◽  
Solid State Method ◽  
Gap Energy ◽  
Wavelength Absorption ◽  
State Method

<p>TiO<sub>2</sub> Anatase activities should be increased from the UV to the visible light photocatalytic activity of TiO<sub>2</sub> to increase anatas. One efforts to optimize TiO<sub>2</sub> anatase activity is doping by using dopant vanadium(V). Synthesis method which is used in this research is a solid reaction method. The steps being taken in this methods include grinding and heating at high temperatures. Dopant concentrations of vanadium(V) which are used in the research was 0.3%, 0.5% and 0.7%. and the characterization used is X-ray diffraction and UV-Vis Diffuse Reflectance Spectroscopy. The result shows that there are a changing of particle size, band gap energy, and absorption of TiO<sub>2</sub> anatas wavelength because of dopan vanadium(V) addition. While TiO<sub>2</sub>’s structure does not change. The crystal sizes of each TiO<sub>2</sub> without doping, V-TiO<sub>2</sub> 0,3%, 0,5% and 0,7% are 53.21 nm, 47.67 nm, 79.65 nm dan 68.99 nm.  Band gap energy of each TiO<sub>2</sub> without doping, V-TiO<sub>2</sub> 0,3%, 0,5% dan 0,7% are 3.309 eV, 3.279 eV, 3.270 eV and 3.259 eV. While wavelength absorption of each TiO<sub>2</sub> without doping, V-TiO<sub>2</sub> 0,3%, 0,5% and 0,7% are 374.9 nm, 378.4 nm, 379.5 nm and 380.8 nm.<em> </em></p><p class="BodyAbstract"> </p><strong><em>Keywords</em>:</strong> <em>Synthesis, titanium dioxide, vanadium(V), solid state method</em>

Influence of Nitrogen Pressure and TiN Addition on Combustion Synthesis of Ti2AlN Powders

2012 ◽  
Vol 624 ◽  
pp. 5-8
Author(s):  
Jia Jin Tian ◽  
Feng Rui Zhai ◽  
Li Li Zhang ◽  
Hong Wei Zhang ◽  
Zhong Zhou Yi
Keyword(s):  
Combustion Synthesis ◽  
Raw Materials ◽  
Low Cost ◽  
Synthesis Method ◽  
Nitrogen Compound ◽  
Combustion Method ◽  
Nitrogen Pressure ◽  
Small Sample ◽  
Optimum Process ◽  
Xrd Diffraction

It has a relatively rapid reaction with self-propagating combustion method to synthesize Ti-Al-N powder. This can effectively avoid uneven phenomenon of aluminum melting reunion during the reaction of raw materials. So you can use lower-cost aluminum as raw materials. In addition, the combustion synthesis method also has a simple process and low-cost advantage. Thus this method has the potential to become the optimum process method to prepare Ti2AlN and Ti4AlN3. In this paper, Ti, Al elemental powders and N2 were used as raw materials. The powder of Ti2AlN was successfully prepared for the first time by combustion synthesis method. This substance is a nitrogen compound of single-phase and three yuan. The results from the XRD diffraction analysis and SEM show that synthetic product is high purity Ti2AlN with a small sample to combustion synthesis when the pressure of nitrogen is in 5 MPa, but the content of synthesis products Ti2AlN is small when the sample is magnified, and the TiN and AlN has a higher content. It can burn synthetic Ti2AlN to control the nitrogen pressure and add the amount of TiN, and the pressure of N2 is better 2 MPa, and the amount of TiN added is better 30 wt.%.

scholarly journals A Physical Chemistry Study of Black Powder Materials by Solution Combustion Synthesis Method

2021 ◽  
Vol 10 (2) ◽  
pp. 93-103
Author(s):  
Fitria Hidayanti ◽  
Kiki R. Lestari ◽  
Nano Sujani ◽  
Jarot Raharjo
Keyword(s):  
Combustion Synthesis ◽  
Lanthanum Oxide ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Synthesis Temperature ◽  
Powder Sample ◽  
Synthesis Process ◽  
Solution Combustion ◽  
Black Powder ◽  
X Ray

A study on the synthesis of black powder (La2NiO4) material using the solution combustion synthesis method at a variation of synthesis temperature of 60, 70, and 80°C was carried out. It produces a mass of black powder of 2 grams by four times of synthesis process. Then, material characterization was performed on the black powder samples obtained by using X-ray Diffraction (XRD) to determine the phases formed, Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy (SEM-EDS) to determine the morphology and analyze the composition elemental on the microscale and Fourier Transform Infra-Red (FTIR) to determine chemical bonds. From the whole black powder sample, XRD analysis showed the phases of Dilantanum Nickel Tetraoxide (La2NiO4), Nickel Oxide (NiO), Lanthanum Oxide (La2O3), and Lanthanum Oxide Ht x-form (La2O3 Ht (x-form)). In addition, it was seen from the visible compositions of the phases that the NiO phase looks more dominant and the variation of the synthesis temperature shows that the La2O3 phase was increasing. This was supported by the EDS analysis, which showed that the EDS spectrum contains elements La, Ni, and O where the element O indicates that oxidation occurs in the elements Ni and La. On the other hand, the SEM analysis results confirm that the black powder sample contains the elements La and Ni, based on the high and low electron images contained in the morphology of the black powder sample. In addition, it was also known that the particles in the black powder sample were micron size and had porous morphology. This occurs due to rapid thermal decomposition events and excessive gas development. In addition, FTIR analysis showed that the O-H bond had been reduced and there are still C-O and C-H bonds indicating the presence of organic elements possessed by glycine.

Formation of metal-carbon nanocomposites based on Cu-Fe alloy nanoparticles and carbonized polyacrylonitrile

2021 ◽  
Vol 1 ◽  
pp. 58-66
Author(s):  
A.A. Vasilev ◽  
◽  
E.L. Dzidziguri ◽  
M.N. Efimov ◽  
D.G. Muratov ◽  
...  
Keyword(s):  
Particle Size ◽  
Carbon Nanostructures ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Carbon Matrix ◽  
Synthesis Temperature ◽  
Average Particle ◽  
Synthesis Of Nanoparticles ◽  
Fe Nanoparticles ◽  
Average Size

A method for the synthesis of nanoparticles of the Cu-Fe bimetallic system with limited mutual solubility of the components is proposed. The synthesis method consists of a one-stage process of IR pyrolysis of precursors in the form of films obtained from a joint solution of polyacrylonitrile and hydrates-nitrates of iron and copper. The effect of the synthesis temperature on the structure formation of the nanocomposites and the phase composition of bimetallic Cu-Fe nanoparticles dispersed in the carbon matrix was studied. The analysis showed a simultaneous presence of Fe and Cu phases in nanocomposites, presumably with a low solubility of the components. The average particle size is 14-17 nm and changes insignificantly with an increase in the synthesis temperature from 400 to 700°C. An increase in the synthesis temperature to 800°C led to a broadening of the particle size distribution and the increase in the average size. The formation of complex carbon nanostructures on Cu-Fe nanoparticles is found.

scholarly journals Microwave-Assisted Combustion Synthesis of Nanocrystalline ZnO Powders Using Zinc Nitrate and Various Amount of Organic Fuels as Reactants: Influence of Reactant Parameters - A Status Review

Nano Hybrids ◽  
2014 ◽  
Vol 6 ◽  
pp. 75-110
Author(s):  
L.C. Nehru ◽  
C. Sanjeeviraja
Keyword(s):  
Combustion Synthesis ◽  
Flame Temperature ◽  
Synthesis Method ◽  
Zinc Nitrate ◽  
Adiabatic Flame Temperature ◽  
Molar Ratios ◽  
Microwave Assisted ◽  
Organic Fuels ◽  
Zno Powders ◽  
Xrd Techniques

Nanocrystalline ZnO powders have been synthesized by a novel and simple microwave-assisted combustion synthesis method using urea, glycine, carbohydrazine and citric acid as fuels and zinc nitrate as oxidant. The starting materials were directly mixed and a slurry precursor with high homogeneity was formed due to the hygroscopicity of the reactants. The precursor could be ignited at room temperature, resulting in dry, loose and voluminous ZnO powders. An interpretation based on an adiabatic flame temperature, amount of gases produced during reaction for various fuel-to-oxidizer molar ratios (ψ), has been proposed for the nature of combustion and its correlation with the characteristics of as-synthesized product. The variation of adiabatic flame temperature (Tad) with the ψ value was calculated theoretically according to the thermodynamic concept. The reaction process of the precursor was investigated by XRD techniques.

Obtainment of α-Tricalcium Phosphate by Solution Combustion Synthesis Method Using Urea as Combustible

2008 ◽  
Vol 396-398 ◽  
pp. 591-594 ◽  
Author(s):  
Tiago M. Volkmer ◽  
L.L. Bastos ◽  
V.C. Sousa ◽  
L.A. Santos
Keyword(s):  
Heat Treatment ◽  
Combustion Synthesis ◽  
Tricalcium Phosphate ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Ph Adjustment ◽  
X Ray

The aim of this work is the synthesis of α-tricalcium phosphate by solution combustion synthesis using urea as combustible in the stoichiometric ratio and with excess of combustible. The salts Ca(O3)2.4H2O and (H4)2HPO4 were used as reaction precursors with Ca/P ratio of 1.5. The pH adjustment was made adding nitric acid. A porous foam composed by β-tricalcium phosphate, hydroxyapatite and α or β-dicalcium pyrophosphate were obtained as reaction product. X-ray diffraction was used to identify the phases. The obtainment of α-TCP was possible after a heat treatment where the material was held at 1250°C for 15 hours followed by quenching. Smaller particle size was obtained when four times the stoichiometric ratio of combustible was used in the reaction. α-TCP samples were immersed in SBF in order to verify the biocompatibility.

scholarly journals NEEM (AZADIRACHTA INDICA A. JUSS) AS A SOURCE FOR GREEN SYNTHESIS OF NANOPARTICLES

2018 ◽  
Vol 11 (3) ◽  
pp. 15 ◽  
Author(s):  
Girish K
Keyword(s):  
Green Synthesis ◽  
Plant Extracts ◽  
Azadirachta Indica ◽  
Low Cost ◽  
Synthesis Method ◽  
Neem Extract ◽  
Synthesis Of Nanoparticles ◽  
Potential Applications ◽  
Vast Area ◽  
Biomedical Fields

 Nanoscience has found various applications in different biomedical fields. The synthesis of nanoparticles (NPs) has become a vast area of research due to its potential applications. These particles can be prepared by different chemical, physical, and biological approaches. In recent years, green synthesis of NPs using plant extracts has gained much interest due to non-toxicity and very low cost of synthesis. The plant extracts act both as reducing agent as well as capping agent. Neem (Azadirachta indica A. Juss) is a well-known medicinal plant and has been studied for the biosynthesis of NPs. A. indica has various phytochemicals identified that can reduce the metal ions. The bioreduction of NPs from neem extract is an eco-friendly, low cost, and green synthesis method and these NPs are reported to exhibit good antimicrobial, mainly antibacterial, activity

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