Examination of Natural and Standard Fe3O4 Powders Using X-Ray Absorption Near-Edge Spectroscopy (XANES)

2019 ◽  
Vol 964 ◽  
pp. 40-44 ◽  
Author(s):  
Hariyanto Budi ◽  
Husain Husain ◽  
Lapboonruang Supanun ◽  
Pratapa Suminar
Keyword(s):  
Particle Size ◽  
Data Analysis ◽  
Absorption Edge ◽  
Single Phase ◽  
Precipitation Method ◽  
X Ray ◽  
Xrd Phase Analysis ◽  
Synchrotron Light ◽  
Co Precipitation ◽  
X Ray Absorption

Investigation of Fe K-edge X-Ray Absorption Near Edge Spectroscopy (XANES) spectra of Fe3O4 (FeO.Fe2O3) from natural source compared with the Fe3O4 standard is presented. The natural Fe3O4 powder was prepared from ironstone of Tanah Laut, Kalimantan Selatan by co-precipitation method. XANES measurements in transmission mode were performed at the Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. XRD phase analysis confirms that the synthesized Fe3O4 powder is a single phase, but it cannot determine the proportion of Fe2O3 and FeO in the structure. TEM measurement confirms that the particle size of natural Fe3O4 about 10 nm. Qualitative analysis of the pre-edge XANES data revealed that the absorbing atom in the XAS measurement is Fe3+. Meanwhile, the absorption edge (E0) values of natural and standard Fe3O4 powders were 7126.44 eV and 7125.02 eV, respectively. The proportion was then acquired using XANES data analysis through Linear Combination Fitting (LCF). It was found that the natural Fe3O4 sample consisted of 98 wt. % Fe2O3 and 2 wt.% FeO, while the standard Fe3O4 powder consisted of 96 wt. % Fe2O3 and 4 wt. % FeO. The mechanism of the absorption in both samples is also described and compared.

Structural Properties of Cu-Doped ZnO Prepared by Coprecipitation Method

2021 ◽  
Vol 1028 ◽  
pp. 90-95
Author(s):  
Kharisma Noor Afifah Supoyo ◽  
Mohammad Syaiful Anwar ◽  
Retno Asih ◽  
Malik Anjelh Baqiya ◽  
Prae Chirawatkul ◽  
...  
Keyword(s):  
Structural Properties ◽  
Hexagonal Wurtzite Structure ◽  
Host Lattice ◽  
Precipitation Method ◽  
Zno Nanoparticle ◽  
X Ray ◽  
As Doping ◽  
Refinement Method ◽  
Co Precipitation ◽  
X Ray Absorption

An experimental study to determine the effect of Cu doping on structural properties of ZnO nanoparticle has been conducted. Zn1-xCuxO (CZO) were prepared by co-precipitation method by varying Cu concentration with x = 0.00, 0.10, 0.11 and 0.12. The structural properties of the CZO sample were characterized by X-Ray diffraction (XRD) and X-ray Absorption Spectroscopy (XAS), which consist of XANES (X-ray Absorption Near-Edge Spectroscopy) and EXAFS (Extended X-ray Absorption Fine Structure). XAS measurements were performed in the energy of Cu K-edge and Zn K-edge using synchrotron radiation at SLRI (Synchrotron Light Research Institute) in Thailand. Both Cu K-edge and Zn K-edge XANES spectra indicate that the oxidation states of Cu and Zn ions are 2+. Analysis of XRD data with refinement method using Rietica software confirms the presence of Cu as doping in ZnO host lattice with the crystallite size ranging between 26 and 44 nm. Moreover, it shows that the obtained CZO samples are polycrystalline with (002) predominant reflection and exhibit a hexagonal wurtzite structure.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

Morphology-Controlled CaCO3 Nanostructures by Modified Co-Precipitation in Pulsed Mode

2015 ◽  
Vol 752-753 ◽  
pp. 148-153
Author(s):  
M.M. Nassar ◽  
Taha Ebrahiem Farrag ◽  
M.S. Mahmoud ◽  
Sayed Abdelmonem
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Rotation Speed ◽  
Average Particle Size ◽  
Calcium Nitrate ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray ◽  
Co Precipitation ◽  
Pulsed Mixing

Calcium carbonate nanoparticles and nanorods were synthesized by precipitation from saturated sodium carbonate and calcium nitrate aqueous solutions through co precipitation method. A new rout of synthesis was done by both using pulsed mixing method and controlling the addition of calcium nitrate. The effect of the agitation speed, and the temperature on particle size and morphology were investigated. Particles were characterized using X-ray Microanalysis, X-ray analysis (XRD) and scanning electron microscopy (SEM). The results indicated that increasing the mixer rotation speed from 3425 to 15900 (rpm) decreases the average particle size to 64±7 nm. A rapid nucleation then aggregation induced by excessive shear force phenomena could explain this observation. Moreover, by increasing the reaction temperature, the products were converted from nanoparticle to nanorods. The maximum attainable aspect ratio was 6.23 at temperature of 75°C and rotation speed of 3425. Generally, temperature raise promoted a significant homoepitaxial growth in one direction toward the formation of calcite nanorods. Overall, this study can open new avenues to control the morphology of the calcium carbonate nanostructures.

Preparation of Iron Catalysts Generated from Fe-Coagulated Sludge Produced by Ferric Chloride Coagulation of Wastewater

2014 ◽  
Vol 1025-1026 ◽  
pp. 645-650
Author(s):  
Supranee Foowut ◽  
Tawanrat Palothaisit ◽  
Natthadabhorn Boonlor ◽  
Panida Prompinit ◽  
Pinsuda Viravathana
Keyword(s):  
Specific Surface ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Iron Catalysts ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
X Ray Absorption ◽  
Xanes Analysis

In this work, the FexOy catalysts were prepared by the co-precipitation method. The catalysts were characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and Brunauer-Emmett-Teller (BET) surface analysis. From XRD results, the FexOy with the wastewater to coagulant ratio of 1:2 catalyst (FexOy-1:2) calcined at 600 °C for 6 h showed the presence of the wustite (FeO) form. XANES analysis showed the phase of FeO in FexOy-1:2 calcined at 600 °C for 6 h which corresponded to the result from XRD. The FexOy 1:1 catalyst had higher specific surface area and larger total pore volume compared to the FexOy 1:2 catalyst.

Co-Promoted Cu/ZnO Catalysts for Fischer-Tropsch Synthesis

2017 ◽  
Vol 266 ◽  
pp. 117-121
Author(s):  
Piyasak Akcaboot ◽  
Napat Kanokpornwasin ◽  
Monthida Raoarun ◽  
Patraporn Saiwattanasuk ◽  
Pinsuda Viravathana
Keyword(s):  
Tropsch Synthesis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
Edge Structure ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Cu Foil ◽  
Co Precipitation ◽  
X Ray Absorption

Co-promoted Cu/ZnO catalysts were studied for Fischer-Tropsch synthesis (FTS). All catalysts were prepared by the co-precipitation method, having the mass ratio of Co:Cu:Zn=0 (unpromoted), 0.05, 0.5:1:1, and characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), including X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). From XRD and XAS, the results confirmed the phase transformation of CuO to Cu foil and Co3O4 to Co foil in Co-promoted catalysts after reduction. After FTS reaction testing, the Co-promoted catalysts showed the decrease in methanol selectivity of 15 and 1.6% for 0.05Co-Cu/ZnO and 0.5Co-Cu/ZnO, respectively, and the increase in C5-C15 selectivity during 30 h of reaction.

scholarly journals Crystal structure, optical and magnetic properties of PrFeO3 nanoparticles prepared by modified co-precipitation method

2020 ◽  
Vol 14 (4) ◽  
pp. 355-361
Author(s):  
Anh Nguyen ◽  
Ngoc Nguyen ◽  
Irina Mittova ◽  
Nikolai Perov ◽  
Valentina Mittova ◽  
...  
Keyword(s):  
Particle Size ◽  
Single Phase ◽  
Average Particle Size ◽  
Precipitation Method ◽  
Average Particle ◽  
Strong Adsorption ◽  
Different Temperatures ◽  
Paramagnetic Materials ◽  
Co Precipitation ◽  
Potential Use

In this work, PrFeO3 nanoparticles were synthesized by modified co-precipitation method and annealed at different temperatures up to 850?C. The annealed PrFeO3 nanoparticles have single phase orthorhombic structure and the average particle size of 25-30 nm. Due to the very small particle size the prepared PrFeO3 nanoparticles are capable of being used as photocatalyst materials thanks to their strong adsorption bands at 230-400 nm and 400-800 nm observed from the UV-Vis spectra. Additionally, the PrFeO3 nanoparticles are paramagnetic materials with Hc ~ 10Oe and Mr ~ 0. These findings demonstrate their potential use not only as photocatalysts, but also as magnetic materials.

Study on Preparation of LiNi0.5Co0.2Mn0.3O2 Precursor-Spherical Ni0.5Co0.2Mn0.3O2(OH)2

2015 ◽  
Vol 816 ◽  
pp. 676-681 ◽  
Author(s):  
Xiao Long Qu ◽  
Zheng Fu Zhang ◽  
Jin Cheng ◽  
Xiao Yan Wang
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tap Density ◽  
Homogeneous Particle ◽  
Co Precipitation ◽  
Scanning Electron

The spherical Ni0.5Co0.2Mn0.3(OH)2 powders were prepared by ammonia-hydroxide co-precipitation method. The influence of different synthesizing factors on the precursors characteristic were investigated. The product prepared with optimized condition has tap density of D≥1.7g·cm-3, and middle particle size D50≈3.6μm. The X-ray diffraction (XRD) results showed that the precursor can be indexed by a hexagonal β-Ni (OH)2 structure. The scanning electron microscope (SEM) results showed that the powders had quasi-spherical pattern and homogeneous particle size distribution.

Preparation of Hexagonal Fe3O4 Nanometer Particles via Weakly Magnetic Field Assisted Oxidation Co-Precipitation

2011 ◽  
Vol 418-420 ◽  
pp. 286-292
Author(s):  
Da Wei Hu ◽  
Yan Ming Wang
Keyword(s):  
Magnetic Field ◽  
Particle Size ◽  
Magnetic Particles ◽  
Photoelectron Spectra ◽  
Precipitation Method ◽  
X Ray ◽  
Nanometer Particles ◽  
Weakly Magnetic ◽  
Particle Sizer ◽  
Co Precipitation

This paper utilized a novel oxidative co-precipitation method to synthesis hexagonal Fe3O4 nanometer particles, which assisted by a weakly magnetic field. The crystallinity, morphology, particle size distribution, compositions and magnetic properties of the as-prepared particles were investigated using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), ultrasonic particle sizer (UPS), X-ray photoelectron spectra (XPS) and vibrating sample magnetometer (VSM). The formation mechanism of the hexagonal Fe3O4 nanometer particles, which assisted by a weakly magnetic field was also discussed. The results shown that the as-prepared hexagonal particles were purity magnetite (Fe3O4), and the weakly magnetic field could accelerate the phase transformation from goethite (α-FeOOH) to magnetite (Fe3O4), increase the particle size and uniform the morphology. The values of saturation magnetization (Ms) and coercivity (H) of the hexagonal magnetic particles are 71.05 emu•g-1 and 474.3 Oe, respectively, which contributed to the morphology anisotropy of the particles.

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