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.

Synthesis of (2D) MNPs nanosheets of nickel ferrite using a low-cost co-precipitation process

2018 ◽  
Vol 232-235 ◽  
pp. 48-54 ◽  
Author(s):  
N. Hosni ◽  
K. Zehani ◽  
R. Pires Brazuna ◽  
J. Moscovici ◽  
L. Bessais ◽  
...  
Keyword(s):  
Nickel Ferrite ◽  
Low Cost ◽  
Precipitation Process ◽  
Co Precipitation

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.

Microwave-assisted production of giant graphene sheets for high performance energy storage applications

2014 ◽  
Vol 2 (31) ◽  
pp. 12166-12170 ◽  
Author(s):  
Xiaoxu Liu ◽  
Da Zhan ◽  
Dongliang Chao ◽  
Bingchen Cao ◽  
Jinghua Yin ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Low Cost ◽  
Graphene Sheets ◽  
Microwave Assisted ◽  
Energy Storage Applications

A simple, low-cost and energy-effective method has been developed to fabricate giant graphene sheets by double microwave assisted exfoliations.

In situ growth of MnO2 nanosheets on activated carbon fibers: a low-cost electrode for high performance supercapacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (18) ◽  
pp. 14819-14825 ◽  
Author(s):  
Kai Zhu ◽  
Yu Wang ◽  
Joel A. Tang ◽  
Hailong Qiu ◽  
Xing Meng ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Hydrothermal Method ◽  
Carbon Fibers ◽  
High Performance ◽  
Low Cost ◽  
Activated Carbon Fibers ◽  
In Situ Growth ◽  
Mno2 Nanosheets ◽  
Microwave Assisted

MnO2 nanosheets were successfully grown in situ on the surface of activated carbon fibers (ACFs) via a facile microwave-assisted hydrothermal method.

High Performance Humidity Sensor Based on ZnO Nanoparticles Synthesized by Co-Precipitation Method

2016 ◽  
Vol 848 ◽  
pp. 99-102 ◽  
Author(s):  
Theerapong Santhaveesuk ◽  
Kwunta Siwawongkasem ◽  
Siriwimon Pommek ◽  
Supab Choopun
Keyword(s):  
Sodium Hydroxide ◽  
Zno Nanoparticles ◽  
High Performance ◽  
Humidity Sensor ◽  
Raw Materials ◽  
Low Cost ◽  
Zinc Nitrate ◽  
Precipitation Method ◽  
Zno Particles ◽  
Co Precipitation

ZnO nanoparticles were successfully synthesized by a low cost co-precipitation method using zinc nitrate and sodium hydroxide as the raw materials. It was observed that the synthesized temperatures greatly effect on the size of ZnO nanoparticles. The lower synthesized temperatures resulted in the smaller nanoparticles. By adjusting the mole ratio of sodium hydroxide, the size of ZnO nanoparticles was also changed. The smallest ZnO particles was 47 nm obtained with 0.7 mole of sodium hydroxide. The smallest ZnO nanoparticles from each synthesized temperatures were fabricated as humidity sensor, showing an impressive performance under different relative humidity (17-94% RH). It should be noticed that the ZnO nanoparticles humidity sensor synthesized at 75 °C exhibited high response for 2 times higher than that of synthesized at 95 °C. This is attributed to the higher surface area of ZnO nanoparticles for absorbed water molecule.

Syntheses of Hematite (α-Fe2O3) Nanoparticles Using Microwave-Assisted Calcination Method

2013 ◽  
Vol 737 ◽  
pp. 197-203 ◽  
Author(s):  
Tati Nurhayati ◽  
Ferry Iskandar ◽  
Khairurrijal ◽  
Abdullah Mikrajuddin
Keyword(s):  
Microwave Heating ◽  
Heating Time ◽  
Average Particle ◽  
Hematite Nanoparticles ◽  
Sem Images ◽  
Calcination Process ◽  
Microwave Assisted ◽  
Crystallite Sizes ◽  
Calcination Method ◽  
Xrd Patterns

Hematite (α-Fe2O3) nanoparticles were synthesized from the solution of FeCl3.6H2O and NaOH in water using microwave-assisted calcination method. The syntheses were initially carried out by microwave heating and completed by a calcination process using a simple heating method. The effect of microwave heating time, calcination temperature, and calcination time were investigated. The XRD patterns demonstrated that the obtained nanoparticles are pure hematite. Using the Scherrer method, the average crystallite sizes of hematite nanoparticles were in the range of 35.6 to 54.4 nm. The obtained hematite nanoparticles were spherical with the average particle sizes ranging from 91 to 116 nm as confirmed by the SEM images.

Role of Particle Size on Structural and Magnetic Behavior of Nanocrystalline Cu-Ni Ferrite

2011 ◽  
Vol 171 ◽  
pp. 79-91 ◽  
Author(s):  
S.N. Dolia
Keyword(s):  
Particle Size ◽  
Saturation Magnetization ◽  
Fine Particles ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Nano Particles ◽  
Blocking Temperature ◽  
Precipitation Method ◽  
Xrd Patterns ◽  
Co Precipitation

Particle size has significant effect on the magnetic properties of fine particles. In this work, Cu0.2Ni0.8Fe2O4 nano-particles have been synthesized by the co-precipitation method. Different particle sizes were obtained by annealing the samples at various temperatures. The X-ray diffraction (XRD) patterns confirm the formation of cubic spinel structure. The particle size was found to enhance with increasing the annealing temperature. The saturation magnetization and the blocking temperature increase with particle size, which is a typical characteristic of the superparamagnetic behaviour. The dc magnetization measurements show that the samples are superparamagnetic above the blocking temperatures and the blocking temperature of the nanoparticles correlates with the size of the nanoparticles that is found to increase as the function of the particle size. The hysteresis curves show reduction in saturation magnetization in case of nanoparticles as compared to their bulk counterparts. This has been explained on the basis that the magnetic moments in the surface layers of a nanoparticle are in a state of frozen disorder. However, the saturation magnetization increases with particle size, which is a characteristic property of the single domain superparamagnetic particles.

scholarly journals Co-precipitation Synthesis with a Variation of the Sulphur Composition of Kesterite Phase Cu2ZnSnS4 (CZSS) without Annealing Process

2021 ◽  
Vol 32 (2) ◽  
pp. 27-39
Author(s):  
Krishan Pal ◽  
Dheeraj Kumar Maurya ◽  
Priyanka Chaudhary ◽  
Khem Bahadur Thapa ◽  
Bal Chandra Yadav
Keyword(s):  
Single Phase ◽  
Vacuum Annealing ◽  
Low Cost ◽  
Precipitation Method ◽  
Stoichiometric Ratio ◽  
Quaternary Compound ◽  
Crystallite Sizes ◽  
Copper Zinc ◽  
High Absorption Coefficient ◽  
Co Precipitation

Commercially available compound CuInGa (S, Se) can be replaced with emerging quaternary compound Cu2ZnSnS4 (Copper Zinc Tin Sulphur or CZSS) for photovoltaic applications due to the high absorption coefficient and optimum bandgap. Unstable sulphur and the co-existence of binary and ternary phases in CZSS are the main obstacles for a single-phase kesterite quaternary compound. To overcome these issues, the researchers are synthesising the CZSS in presence of sulphur and selenium environment. The sulphurization and selenization are the constraints for the synthesis of CZSS and these processes make it costlier. In the present work, the wet-chemical method (i.e., co-precipitation method) was used to synthesise CZSS without vacuum annealing where the sulphur constituent was controlled by changing the stoichiometric ratio. X-ray diffraction (XRD) and Raman analysis confirm that the synthesised CZSS was in polycrystalline and single-phase kesterite nature. The average crystallite sizes for thiourea 16, 18, 20 mmol were found 15 nm, 17 nm and 17 nm, respectively. Surface morphology of the as-prepared film was identified by scanning electron microscope (SEM) and optical bandgap of the film was obtained ~1.33 eV by UV-visible (UV-vis) analysis. The 18 mmol of thiourea with stoichiometric ratio 4:2:2:9 is found the best optimisation for synthesising the CZSS without vacuum annealing by the co-precipitation method. Thus, the thin film of such synthesised CZSS may be employed for the low-cost photovoltaic application.

Microwave-Assisted Organic Acid Hydrolysis of Corncob in Bioethanol Production

2014 ◽  
Vol 1033-1034 ◽  
pp. 151-154
Author(s):  
Sininart Chongkhong ◽  
Chakrit Tongurai
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Organic Acid ◽  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Low Cost ◽  
Heating Time ◽  
Microwave Assisted ◽  
Bakery Yeast ◽  
Hydrolysis Of

The microwave-assisted hydrolysis of carbohydrate from corncob using acetic acid was investigated by response surface methodology. The sequence of variables affecting total reducing sugar concentration in the hydrolyzate was the ratio of corncob to acid solution > acid concentration > microwave heating time. The highest 84.2 g/L glucose concentration was obtained by 0.5 M acetic acid concentration with 0.40:1 corncob to acid solution ratio at 900 W microwave power for 10 min. The hydrolyzate prepared from the optimal hydrolysis condition was fermented by 8%w bakery yeast with pH 5.25 at 28°C for 62 h to achieve the optimum ethanol concentration of 32.2 g/L. This proposed that microwave-assisted organic acid hydrolysis is potential for producing fermentable sugars, and suggested that a two-step process for the ethanol is the satisfied production because of low cost, save energy consumption and friendly to environment.

Exploring the characterization of Ni doped MgO nanoparticles using co-precipitation method

2020 ◽  
Vol 3 (1) ◽  
pp. 30-33
Author(s):  
Muthulakshmi M ◽  
Madhumitha G
Keyword(s):  
Magnesium Oxide ◽  
Analytical Techniques ◽  
Nickel Chloride ◽  
Precipitation Method ◽  
Crystalline Powder ◽  
High Melting Point ◽  
Design Synthesis ◽  
Mgo Nanoparticles ◽  
Co Precipitation

Nanotechnology is a field of applied science focused on design, synthesis and characterization of nanomaterials. The nickel and magnesium have improved their applications in transparent electrodes and nano electronics. In addition, magnesium oxide has moisture resistance and high melting point properties. In the present work has been carried out in the development of green crystalline powder of nickel doped magnesium oxide nanoparticles by Co-precipitation method, from the mixture of nickel chloride and magnesium chloride with KOH as solvent. From the XRD results, crystalline size of the particle can be observed. Spherical structure of Ni doped MgO nanoparticles were indicated by SEM results and powdered composition of samples were obtained from FTIR. EDAX represents the peak composition of the nanoparticle. The above analytical techniques have confirmed that the Ni doped MgO nanoparticles obtained from the mixture of NiCl2 and MgCl2.

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