Microwave-assisted combustion synthesis of Ni powder using urea

2006 ◽  
Vol 21 (7) ◽  
pp. 1664-1673 ◽  
Author(s):  
Ranjan K. Sahu ◽  
A.K. Ray ◽  
S.K. Das ◽  
A.J. Kailath ◽  
L.C. Pathak
Keyword(s):  
Magnetic Measurement ◽  
Combustion Method ◽  
Exothermic Peak ◽  
Combustion Reaction ◽  
Molar Ratio ◽  
Cubic Phase ◽  
Solution Combustion ◽  
Force Microscopy ◽  
Microwave Assisted ◽  
Ni Powder

A novel microwave-assisted combustion method was used to prepare Ni powder. The method involves the combustion reaction of nickel nitrate and urea as a fuel in the microwave field. The initiation of the exothermic peak of the combustion reaction was found to vary as a function of urea content. The microwave-prepared Ni powder was characterized using x-ray diffraction (XRD), scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, thermogravimetric (TG) analysis, differential thermal analysis (DTA), and magnetic measurement. The XRD pattern revealed that the Ni powder crystallizes with the cubic phase when the molar ratio of fuel to nitrate is varied between 5:1 and 6:1. Above or below that molar ratio, NiO phase coexists as an impurity along with the Ni phase. The magnetization value of Ni measured at room temperature is 53.5 Am2/kg, which is close to the value observed for commercial Ni powder (55.0 Am2/kg). The mechanism for the formation of the Ni and NiO phase is discussed based on the infrared, TG, and DTA data. The method shows that highly pure Ni powder can be prepared using urea as a fuel and microwaves as a source of energy via the solution combustion method.

scholarly journals Influence of the La3+, Eu3+, and Er3+ Doping on Structural, Optical, and Electrical Properties of BiFeO3 Nanoparticles Synthesized by Microwave-Assisted Solution Combustion Method

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Angelika Wrzesinska ◽  
Alexander Khort ◽  
Izabela Bobowska ◽  
Adam Busiakiewicz ◽  
Aleksandra Wypych-Puszkarz
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Bismuth Ferrite ◽  
Solution Combustion Synthesis ◽  
Combustion Method ◽  
Band Gap Energy ◽  
Rare Earth Doping ◽  
Optical And Electrical Properties ◽  
Solution Combustion ◽  
Microwave Assisted

In this study, nanocrystalline (18–28 nm) perovskite-like bismuth ferrite rare earth-doped powders (Bi0.9RE0.1FeO3, where RE = La (BLaFO), Eu (BEuFO), and Er (BErFO)) were obtained by microwave-assisted modification of solution combustion synthesis (SCS). The influence of high load La3+, Eu3+, and Er3+ doping on structural, optical, and electrical properties of BiFeO3 was investigated. It was found that rare earth doping along with fast phase formation and quenching significantly distorts the crystal cells of the obtained materials, which results in the formation of mixed rhombohedral- (R3c-) orthorhombic (Pbnm) crystal structures with decreased lengths of Bi-O and Fe-O bonds along with a decreasing radius size of doping ions. This promotes reduction of the optical band gap energy and suppression of ionic polarization at high frequencies and results in enhanced dielectric permittivity of the materials at 1 MHz.

scholarly journals Effect of CeO2-ZnO Nanocomposite for Photocatalytic and Antibacterial Activities

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 817
Author(s):  
Asad Syed ◽  
Lakshmi Sagar Reddy Yadav ◽  
Ali H. Bahkali ◽  
Abdallah M. Elgorban ◽  
Deshmukh Abdul Hakeem ◽  
...  
Keyword(s):  
Surface Defects ◽  
Uv Light ◽  
Antibacterial Properties ◽  
Combustion Method ◽  
Antibacterial Activities ◽  
Cubic Phase ◽  
Solution Combustion ◽  
Tem Analysis ◽  
Bet Specific Surface Area ◽  
The Impact

The impact of a CeO2-ZnO nanocomposite on the photocatalytic and antibacterial properties compared to bare ZnO was investigated. A CeO2-ZnO nanocomposite was synthesized using Acacia nilotica fruit extract as a novel fuel by a simple solution combustion method. The obtained CeO2-ZnO nanocomposite was confirmed structurally by XRD, FTIR, Raman and UV-DRS and morphologically by SEM/TEM analysis. The XRD pattern indicates the presence of both hexagonal Wurtzite-structured ZnO (major) and cubic-phase CeO2 (minor). FTIR shows the presence of a Ce-O-Ce vibration at 468 cm−1 and Zn-O vibration at 445 cm−1. The existence of a band at 460 cm−1 confirmed the F2g Raman-active mode of the fluorite cubic crystalline structure for CeO2. Diffused reflectance spectroscopy was used to estimate the bandgap (Eg) from Kubelka–Munk (K–M) theory which was found to be 3.4 eV. TEM analysis shows almost spherical-shaped particles, at a size of about 10–15 nm. The CeO2-ZnO nanocomposite shows a good BET specific surface area of 30 m2g−1. The surface defects and porosity of the CeO2-ZnO nanocomposite caused methylene blue (MB) dye to degrade under sunlight (88%) and UV light (92%). The CeO2-ZnO nanocomposite also exhibited considerable antibacterial activity against a pathogenic bacterial strain.

Thermoluminescence properties of MgO:Al3+,Li+ prepared by microwave-assisted solution combustion method

2020 ◽  
Vol 582 ◽  
pp. 412008 ◽  
Author(s):  
S.J. Mofokeng ◽  
L.L. Noto ◽  
D.V. Mlotswa ◽  
V.R. Orante-Barrón ◽  
M.S. Dhlamini
Keyword(s):  
Combustion Method ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Microwave Assisted

Microwave-Assisted Solution Combustion Synthesis and Characterization of Thermoelectric Ca3Co2O6 Powders

2013 ◽  
Vol 802 ◽  
pp. 84-88
Author(s):  
Sagulthai Kahatta ◽  
Nopsiri Chaiyo ◽  
Chesta Ruttanapun ◽  
Wicharn Techitdheera ◽  
Wisanu Pecharapa ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Solution Combustion Synthesis ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
X Ray ◽  
Microwave Assisted ◽  
Product Characterization ◽  
Rhombohedral Crystal Structure ◽  
Rhombohedral Crystal

The microwave-assisted solution combustion synthesis was applied to the initial synthesizing of Ca3Co2O6powder using glycine as a fuel and nitrate as an oxidant. The as-synthesized powders were calcined at 700-1,000ºC for 4h. Product characterization was performed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Scanning electron microscope (SEM). The fuel-to-oxidizer molar ratio was found to affect the combustion reaction and character of the powder obtained. The phase composition of powder after calcination at various temperatures has shown that the formation of Ca3Co2O6occurs directly. The calcined powder possesses a rhombohedral crystal structure with an X-ray diffraction pattern that could be matched with the Ca3Co2O6JCPDS: 89-0629. This method is a simple way of synthesizing fine Ca3Co2O6powder with a low calcination temperature.

scholarly journals Microwave-Assisted Synthesis of Mixed Metal-Oxide Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Akrati Verma ◽  
Reena Dwivedi ◽  
R. Prasad ◽  
K. S. Bartwal
Keyword(s):  
Oxidation State ◽  
Combustion Method ◽  
Mixed Metal Oxide ◽  
Average Particle ◽  
Particle Sizes ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Xps Spectra ◽  
Mixed Metal ◽  
Microwave Assisted

Nanoparticles of mixed metal oxides, ZrO2, ZrTiO4, and ZrV2O7 were prepared by microwave-assisted citrate sol-gel and solution combustion method. The prepared nanoparticles were characterized for their structural details using XRD and TEM techniques. The broadening of Raman bands is ascribed to local compositional fluctuations or local positional disordering produced due to random distribution of Zr4+ and Ti4+between equivalent sites. The XPS spectra confirm the incorporation of Ti in ZrO2 and suggest Zr as well as Ti in +4 oxidation state. Gelation and fast combustion seem to be the reason for smaller particle sizes. ZrV2O7 nanocrystalline material was synthesized by microwave- assisted solution combustion method. Low angle powder XRD measurements confirm the mesoporous nature of the prepared material. The effect of calcination temperature on the phase transformation of the materials has been investigated. Among tetragonal, monoclinic, and cubic phases, the monoclinic phase is predominant at higher calcinations temperature. The XPS confirms the incorporation of V2O5 in ZrO2 and suggests that Zr and V are in the same oxidation state (+4). The average particle sizes for ZrO2, ZrTiO4, and ZrV2O7 were found to be in the ranges of 5–10 nm, 2–5 nm, and 10–50 nm, respectively.

Nanomaterial Preparations by Microwave-Assisted Solution Combustion Method and Material Properties of SnO2 Powder - A Status Review

2011 ◽  
Vol 671 ◽  
pp. 69-120 ◽  
Author(s):  
L.C. Nehru ◽  
V. Swaminathan ◽  
M. Jayachandran ◽  
C. Sanjeeviraja
Keyword(s):  
Structural Parameters ◽  
Combustion Process ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Solution Combustion ◽  
Xrd Pattern ◽  
Microwave Assisted ◽  
Heat Treated ◽  
Sno2 Sample ◽  
Crystal Density

A nanocrystalline tin oxide (SnO2) powders have been prepared by a simple, low-temperature initiated, self-propagating and gas producing by microwave-assisted solution combustion process. The effects of temperature on crystalline phase formation and particle size of nanocrystalline SnO2 and its structure have been investigated. It is observed that heat-treated upto 800°C shows tetragonal phase SnO2. It was observed that the average crystallite size of the annealed SnO2 samples is in the range 9 - 43 nm through controlled heat treatment process. The crystal density of the as-prepared powder is 5.850g cm-3 where as the bulk density is 6.998 g cm−3. The microstructure and morphology were studied by scanning electron microscope (SEM) and HRTEM it is interesting to note that as-prepared SnO2 sample are almost spherical in shape and average agglomerate crystal size of 0.2 – 0.4 μm with increase in calcination temperature, the samples become better morphology than the as-prepared sample. The crystallographic parameters were refined by XRD pattern and Rietveld refinement using TOPAS-3 and Diamond software was used to construct the structural parameters.

scholarly journals Synthesis, Characterization and Catalytic Activity of Ternary Oxide Catalysts Using the Microwave-Assisted Solution Combustion Method

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4607
Author(s):  
Kawthar Frikha ◽  
Lionel Limousy ◽  
Jamel Bouaziz ◽  
Kamel Chaari ◽  
Simona Bennici
Keyword(s):  
Transition Metal ◽  
Co Oxidation ◽  
Combustion Method ◽  
Oxide Catalysts ◽  
Metal Species ◽  
Ternary Oxide ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Oxidation Activity ◽  
Microwave Assisted

Ni−Co−Al, Ni−Cu−Al and Co−Cu−Al ternary oxide catalysts, with a fixed 5 wt% transition metal loading, were prepared by the microwave-assisted solution combustion method and tested in CO oxidation. The bulk and surface properties of the catalysts were investigated, using XRD, N2 adsorption–desorption, SEM, XPS and TEM techniques. XRD, XPS and TEM results revealed that nickel and cobalt were present as spinels on the surface and in the bulk. Differently, copper was preferentially present in “bulk-like” CuO-segregated phases. No interaction between the couples of transition metal species was detected, and the introduction of Cu-containing precursors into the Ni−Al or Co−Al combustion systems was not effective in preventing the formation of NiAl2O4 and CoAl2O4 spinels in the Ni− or Co-containing catalysts. Copper-containing catalysts were the most active, indicating that copper oxides are the effective active species for improving the CO oxidation activity.

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