scholarly journals Multifunctional Electrochemical Properties of Synthesized Non-Precious Iron Oxide Nanostructures

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 751 ◽  
Author(s):  
Ruby Phul ◽  
M. A. Majeed Khan ◽  
Meryam Sardar ◽  
Jahangeer Ahmed ◽  
Tokeer Ahmad

Magnetic Fe3O4 nanostructures for electrochemical water splitting and supercapacitor applications were synthesized by low temperature simple wet-chemical route. The crystal structure and morphology of as-acquired nanostructures were examined by powder X-ray diffraction and transmission electron microscopy. Magnetic measurements indicate that the as-synthesized Fe3O4 nanostructures are ferromagnetic at room temperature. The synthesized nanostructures have a high-specific surface area of 268 m2/g, which affects the electrocatalytic activity of the electrode materials. The purity of the as-synthesized nanostructures was affirmed by Raman and X-ray Photoelectron studies. The electrochemical activity of the magnetic iron oxide nanoparticles (MIONPs) for the hydrogen evolution reaction (HER) and supercapacitors were investigated in alkaline medium (0.5 M KOH) versus Ag/AgCl at room temperature. The electrocatalysts show low onset potential (~0.18 V) and Tafel slope (~440 mV/dec) for HER. Additionally, the specific capacitance of MIONPs was investigated, which is to be ~135 ± 5 F/g at 5 mV/s in 1 M KOH.

2012 ◽  
Vol 67 (11) ◽  
pp. 1185-1190 ◽  
Author(s):  
Jin-Li Qi ◽  
Wei Xu ◽  
Yue-Qing Zheng

A new Cu(II) complex was prepared at room temperature from the reaction of p-formylbenzoic acid, phenanthroline, CuCl2⋅2H2O, and NaOH under ethanolic aqueous conditions. The complex has been characterized by X-ray diffraction, IR spectroscopy, TG-DTA analyses, and magnetic measurements. Single-crystal X-ray diffraction analysis indicated that the complex crystallizes in the triclinic space group P1̄ with the cell dimensions a=7.875(2), b=10.724(2), c=15.317(3) Å , α =102.65(3), β =93.71(3), γ =107:64(3)°. The Cu atoms are in the environment of distorted CuN2O3 tetragonal pyramids. These discrete complex molecules are packed through intermolecular π...π-stacking interactions and C-H...O hydrogen bonds forming a supramolecular structure. The title complex obeys the Curie-Weiss law with a Curie constant C=0:53 cm3 K mol-1 and a Weiss constant θ = -0:27 K. The shape of the xmT curve is characteristic of weak ferromagnetic interactions between the Cu(II) centers from 300 to 7 K, while there are weak antiferromagnetic interactions below 7 K.


2009 ◽  
Vol 7 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Zehra Durmus ◽  
Hüseyin Kavas ◽  
Abdulhadi Baykal ◽  
Muhammet Toprak

AbstractA novel environmental friendly, room temperature route using an ionic liquid 1-n-butyl-3-methylimidazolium hydroxide ([BMIM]OH) for the synthesis of Mn3O4 nanoparticles is presented. The product was characterized using Fourier transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. Phase purity was confirmed by XRD, and X-ray line profile fitting determined a crystallite size of 42 ± 11 nm. TEM analysis revealed various morphologies. EPR measurements have indicated the existence of long-range interactions, due to the wide range of particle sizes and morphologies observed.


2011 ◽  
Vol 10 (01n02) ◽  
pp. 237-240 ◽  
Author(s):  
J. P. BORAH ◽  
C. BORGOHAIN ◽  
K. C. SARMA ◽  
K. K. SENAPATI ◽  
P. PHUKAN

The synthesis of composite magnetic nanomaterials has received increasing attention due to their electronic, magnetic, catalytic, and chemical or biological sensing properties. We have prepared cobalt ferrite–zinc sulfide nanocomposites by a chemical route. The synthesized nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and photoluminescence spectrometer (PL). The fluorescent magnetic nanoparticles (FMNPs) had a typical diameter of 30±5 nm and saturation magnetization of 5.8 emu g-1 at room temperature. So, these FMNPs may be potentially applied in different fields such as optoelectronic devices, biolabeling, imaging, drug targeting, bioseparation, magnetic fluid hyperthermia, etc.


2009 ◽  
Vol 152-153 ◽  
pp. 205-208 ◽  
Author(s):  
H. Arabi ◽  
S. Nateghi ◽  
S. Sadeghi

Iron oxide nanoparticles were synthesis by reverse micelle method. X-ray diffraction technique and vibration sample magnetometer were applied to characterize the produced samples at different conditions and parameters for synthesis route. There is no significant difference between samples prepared at 5°C and room temperature except a better crystalline at room temperature. The molar ratio of water to surfactant (w parameter) and concentration of the salt solution on size and magnetic properties of nanoparticles have been investigated. Increasing w leads to producing particles with larger size i.e. for w=16.83, 11.22, and 5.6, particles size are 15.22, 11.66 and 10.5 nm, respectively. The size of nanoparticles are in the range of 9 to 20 nanometers


2005 ◽  
Vol 475-479 ◽  
pp. 3729-3732
Author(s):  
Cong Mian Zhen ◽  
Xiao Xia Zhai ◽  
Chengfu Pan ◽  
Xiangfu Nie

FePt/C mutilayer films were successfully prepared by using RF and DC magnetron sputtering system. FePt nanoparticles embedded in a C matrix were formed by consequently annealing. X-ray diffraction (XRD) results show the degree of atomic ordering of the L10 structure increases with higher temperature annealing. Room temperature magnetic measurements reveal that in-plane coercivity HC, and squareness Mr/MS depend on the thickness of carbon layer. Relatively High HC (3245.1Oe) and squareness (0.67) were obtained when the thickness of C layer is 2.0 nm. The carbon layer not only isolates the FePt grain, but also suppresses the growth of fct FePt grains. When the thickness of carbon layer is 2.0 nm, the FePt grain size decreases down to ~20 nm measured by Scan Probe Microscope (SPM). Interactions between particles can be tuned to near zero when we select the proper thickness of C layer.


2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.


2016 ◽  
Vol 81 (11) ◽  
pp. 1251-1262 ◽  
Author(s):  
Oluwafunmilayo Adekunle ◽  
Ray Butcher ◽  
Oladapo Bakare ◽  
Olusegun Odunola

[Cu(phen)2(CH3COO)](ClO4).2H2O (1) and [Cu(bipy)2(CH3COO)]-(ClO4).H2O (2) {phen = 1,10-phenanthroline, bipy = 2,2?-bipyridine}were synthesized and characterized. The complexes were characterized by employying elemental analyses, infrared and UV-Visible spectroscopy, room temperature magnetic measurements and the crystal structures elucidated using X-ray diffraction experiment. The redox properties of the complexes were also investigated. Both structures have a square pyramidal CuN4O chromophore which exhibit significant distortions due to long Cu-O [2.217(3) ? for (1) and 2.179 (1) for (2)] and Cu-N [2.631(2) ? for (1) and 2.714(1) ? for (2)] bonds. This distortion if further shown by the O-Cu-N bond angles [147.71(8) o for (1) and 153.40(5) o for (2)]. The elemental analyses further support the structural details unveiled by the single crystal X-ray diffraction analysis. The infrared spectra shows the acetate vibrational frequencies at 1587 cm-1,1428 cm-1, 1314 cm-1 for (1) and 1571 cm-1, 1441 cm-1, 1319c m-1 for (2) and the perchlo-rate bands at 1059 cm-1, 720 cm-1 (1) and 1080 cm-1,768 cm-1 (2). The broad d-d bands for the copper ion at 14,514 cm-1(1) and 14,535 cm-1(2) support the adoption of square pyramid geometries. The magnetic moments for the two complexes are 1.83 B.M for (1) and 1.72 B.M for (2). The peak to peak values of the two complexes show that the electrode reactions are quasi-reversibile with ?Ep = 0.023V (1) and 0.025V for (2). In both structures, there are ?-? intermolecular interactions in addition to hydrogen bonding between the units.


2020 ◽  
Vol 10 (2) ◽  
pp. 123-126
Author(s):  
Debasish Aich ◽  
Pijus Kanti Samanta ◽  
Satyajit Saha ◽  
Tapanendu Kamilya

Background: Iron oxide (γ-Fe2O3) nanoparticles have been prepared by a simplified coprecipitation method. Methods: X-ray diffraction peaks of the prepared nanoparticles match well with the characteristic peaks of crystalline g-Fe2O3 as per JCPDS data (JCPDS Card No. 39-1346) and absorption peak at 369 nm along with band gap 2.10 eV suggesting the formation of (γ-Fe2O3) nanoparticles. Results: The γ-Fe2O3 nanoparticles are spherical in nature with a diameter around ~10 nm. Conclusion: The crystalline g-Fe2O3 nanoparticles exhibit excellent super-paramagnetic behavior not only at room temperature (300K) but also at a temperature as low as 100K.


2019 ◽  
Vol 9 (1) ◽  
pp. 3794-3799 ◽  

Microwave assisted synthesis technique was used to prepare palladium supported on iron oxide nanoparticles. The advantage of using microwave irradiation as a synthetic tool is due to its unique features as a one step, simple, versatile, and rapid process. The reactants are added simply at room temperature without using high-temperature injection. Hydrazine hydrate was added by the following ratios (0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1, 1.6, and 3) ml to the different prepared samples at room temperature in order to investigate its effect on the catalytic performance of the prepared catalysts. The prepared catalyst could be used as an ideal candidate not only for Pharmaceutical industry through cross-coupling reactions but also for low temperature oxidation catalysis of carbon monoxide and pharmaceutical applications as well. The experimental results showed that Pd/Fe3O4 catalyst has a remarkable catalytic activity for carbon monoxide oxidation catalysis due to the strong interaction between palladium and iron oxide nanoparticles. This may be due to the small particle size (7-14 nm) and concentration ratio of the Pd nanoparticles dispersed on the surface of magnetite (Fe3O4). Those nanoparticles were characterized by various spectroscopic techniques including; X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM) and transmission electron microscopy (TEM).


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Wenhua Zhao ◽  
Zhiqiang Wei ◽  
Li Zhang ◽  
Xiaojuan Wu ◽  
Xuan Wang ◽  
...  

Cr doped Zn1-xCrxS nanorods with different concentration ratio (x=0, 0.01, 0.03, and 0.05) were successfully synthesized by hydrothermal method. The crystal microstructure, morphology, chemical composition, and optical and magnetic properties of the samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS), diffuse-reflectance spectroscopy (DRS), photoluminescence (PL) spectra, and the vibrating sample magnetometer (VSM). All the samples synthesized by this method exhibited single-phase wurtzite structure with good crystallization as demonstrated by XRD studies, which indicated that all Cr ions successfully substituted for the lattice site of Zn2+ and generated single-phase Zn1-xCrxS. DRS revealed the band gap of doped Zn1-xCrxS underwent blue shift compared to that of the bulk ZnS. PL spectra showed obvious ultraviolet emission peak at 375 nm and two blue emissions appear about 500 and 580 nm. The blue emissions intensity of doped samples improved with the increase of Cr concentration, comparing to pure ZnS. Magnetic measurements indicated that the undoped and doped ZnS nanorods exhibited well-defined ferromagnetic behavior at room temperature. The saturation magnetization weakened significantly with increasing Cr concentration comparing to pure ZnS and reached minimum for 3% Cr.


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