scholarly journals Production of an Efficient Magnetic Adsorbent From Babassu Coconut Endocarp and Ni Particles for Easy Dye Removal From Mimetic Contaminated Effluents

Author(s):  
Wanderson S. Silva ◽  
Patrícia F. Santos ◽  
Jair C. C. Freitas ◽  
Miguel A. Schettino ◽  
Edson C. Passamani ◽  
...  

Abstract Ni metal particles, with sizes ranging from 70 to 110 nm, dispersed in activated carbon produced from the babassu coconut endocarp (BAC) were successfully synthesized and evaluated by scanning electron microscopy, dispersive energy X-ray spectroscopy, flame atomic absorption spectroscopy and powder X-ray diffraction. These hybrid BACNi-X materials (where X is the Ni / BAC ratio, equal to 10, 20 or 30) exhibit crystalline Ni particles with suitable magnetic properties, shown by increased saturation magnetization and a gradual reduction in coercive fields (varying 80 to 150 Oe) as the Ni content increases. Relatively large values ​​of pore volume (in the range of 0.28-0.37 cm3/g), specific surface area (560-740 m2/g) are achieved, favoring their applications for magnetic remediation of mimetic contaminated effluents. All hybrid samples were tested positively for the adsorption of methylene blue in contaminated synthetic effluents and the greatest removal was achieved by the hybrid sample BACNi-10, which has the largest specific area and reasonable magnetic properties that allowed the manipulation of the sample by an external field.

2016 ◽  
Vol 20 (06) ◽  
pp. 677-688 ◽  
Author(s):  
Ahmad Shaabani ◽  
Zeinab Hezarkhani

Functionalized wool with cobalt(II), copper(II), and iron(II) tetrasulfophthalocyanine (CoTSPc@wool, CuTSPc@wool, and FeTSPc@wool) have been synthesized and their structures characterized by flame atomic absorption spectroscopy (FAAS), FT-IR, UV-vis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the energy dispersive spectroscopy (EDS) analysis. The catalytic activity of the synthesized catalysts was investigated for the aerobic oxidation of alkyl arenes and alcohols to their corresponding carbonyl compounds in the absence of any co-promoter and additional oxidizing reagent. We found the best catalyst for the mentioned reactions is the CoTSPc@wool from the solvent, conversion, temperature, and reaction time point of views. The synthesized catalysts can be readily recycled and reused for several runs without significant loss of efficiency.


2018 ◽  
Vol 271 ◽  
pp. 112-118
Author(s):  
Jun Ning ◽  
Gerile Mandahu ◽  
Kai Li ◽  
Hasi Chaolu ◽  
Ojin Tegus ◽  
...  

The structure and magnetic properties of the Nd3Fe27.7-xNixTi1.3compounds prepared by arc-melting method have been investigated by means of X-ray diffraction and magnetization measurement. It was found that all the compounds crystallized in Nd3(Fe, Ti)29-type structure with monoclinic symmetry and A2/m space group in concentration range 0.2 ≤x≤ 1.2. The unit cell volume decreased slightly with increasing Ni content. The X-ray diffraction patterns of the magnetically aligned samples showed that all compounds investigated had planar anisotropy. The Spin reorientation phenomena occurred in all the compounds. As the increase of Ni content, the Curie temperature TCmonotonously increased, but the spin reorientation temperature Tsrdid not obviously change. The saturation magnetization Ms of the compounds decreased monotonously with increasing Ni content at 5 K, 105 K, 205 K, and 305 K. The anisotropy fields Baat 5 K, 305 K and anisotropy constant K2at 305K appeared as a minimum, but the anisotropy constant K1at 305 K appeared as a maximum onx= 0.6.


2013 ◽  
Vol 699 ◽  
pp. 524-529 ◽  
Author(s):  
A. Manikandan ◽  
J. Judith Vijaya ◽  
L. John Kennedy

Pure and Ni-doped ZnFe2O4 nanoparticles, Zn1-xNixFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) were synthesized by microwave combustion method (MCM). The structural, morphological and magnetic properties of the products were determined by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM) and vibrating sample magnetometer (VSM). X-ray analysis showed that all the compositions crystallize with cubic spinel structure. The broadband visible emission is observed in the entire photoluminescence (PL) spectrum and the estimated energy band gap is about 2.1 eV. VSM measurements shows superparamagnetic behavior for lower concentration of Ni (x ≤ 0.2), whereas for higher concentration (x ≥ 0.2), it becomes ferromagnetic. The saturation magnetization (Ms) varies considerably with Ni content to reach a maximum value for Ni0.5Zn0.5Fe2O4 composition, i.e. 57.89 emu/g.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.


2010 ◽  
Vol 654-656 ◽  
pp. 1106-1109
Author(s):  
Ya Qiong He ◽  
Chang Hui Mao ◽  
Jian Yang

Nanocrystalline Fe-Co alloy powders, which were prepared by high-energy mechanical milling, were nitrided under the mixing gas of NH3/H2 in the temperature range from 380°C to 510°C. X-ray diffraction (XRD) was used to analyze the grain size and reaction during the processing. The magnetic properties of the nitrided powders were measured by Vibrating Sample Magnetometer (VSM). The results show that with the appearance of Fe4N phase after nitride treatment, and the grain-size of FeCo phase decreases with the increase of nitridation temperature between 380°C to 450°C.The saturation magnetization of nitrided alloy powder treated at 480°C is about 18% higher than that of the initial Fe-Co alloy powder, accompanied by the reduction of the coercivity. Transmission electron microscope (TEM) was used, attempting to further analyze the effect of Fe4N phase on microstructure and magnetic properties of the powder mixtures.


2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.


2021 ◽  
Vol 21 (11) ◽  
pp. 5592-5602
Author(s):  
Samira Almasi ◽  
Ali Mohammad Rashidi

The effect of the yttria-stabilized zirconia (YSZ) nanoparticle loading in an electro-less bath was considered as one of the vital synthesis variables for control Ni content and microstructure of prepared nanocomposite particles, which are two crucial factors to achieving high-performance SOFC anode. Nanocomposite particles were prepared using a simple electroless method without any expensive pretreatment of sensitizing by Sn2+ ions as well as activating by Pd2+ ions that are usually used to apply nickel coating on the surface of a non-conductive substrate. The process was performed by adding YSZ nanoparticles into NaOH solution, separating them from the solution by the centrifugal method, then providing several water-based nanofluids with different concentrations of activated YSZ nanoparticles, mixing them with NiCI2 solution, followed by adding the hydrazine and then NaOH solution. X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis were used to analyze the prepared nanocomposite particles. It is observed that after adding YSZ nanoparticles into the NaOH solution, the pH of the solution varied gradually from a starting pH of 10.2 to 9. Also, by increasing the YSZ nanoparticles loading in the electroless bath from 76 mg/l to 126 mg/l, the grain size of Ni deposits, the Ni content and the average size of the prepared nanocomposite particles decreased. The electrochemical mechanism previously proposed for the nickel ion reduction was modified, and a novel analytical model was proposed for variation of the efficiency of Ni deposition with YSZ nanoparticles loading.


2007 ◽  
Vol 130 ◽  
pp. 171-174 ◽  
Author(s):  
Z. Stokłosa ◽  
G. Badura ◽  
P. Kwapuliński ◽  
Józef Rasek ◽  
G. Haneczok ◽  
...  

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.


2004 ◽  
Vol 848 ◽  
Author(s):  
Evan Lyle Thomas ◽  
Erin E. Erickson ◽  
Monica Moldovan ◽  
David P. Young ◽  
Julia Y. Chan

AbstractA new member of the LnMIn5 family, ErCoIn5, has been synthesized by a flux-growth method. The structure of ErCoIn5 was determined by single crystal X-ray diffraction. It crystallizes in the tetragonal space group P4/mmm, Z = 1, with lattice parameters a = 4.5400(4) and c = 7.3970(7) Å, and V = 152.46(2) Å3. Electrical resistivity data show metallic behavior. Magnetic susceptibility measurements show this compound to be antiferromagnetic with TN = 5.1 K. We compare these experimental results with those of LaCoIn5 in an effort to better understand the effect of the structural trends observed on the transport and magnetic properties.


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