scholarly journals Synthesis and Characterization of Fe0.8Mn0.2Fe2O4 Ferrite Nanoparticle with High Saturation Magnetization via the Surfactant Assisted Co-Precipitation

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 876
Author(s):  
Kornkanok Rotjanasuworapong ◽  
Wanchai Lerdwijitjarud ◽  
Anuvat Sirivat
Keyword(s):  
Electron Microscope ◽  
Saturation Magnetization ◽  
Photoelectron Spectroscopy ◽  
Sodium Dodecyl ◽  
Ferrite Nanoparticles ◽  
Ferromagnetic Behavior ◽  
X Ray ◽  
Ferrite Nanoparticle ◽  
Co Precipitation ◽  
Surfactant Assisted

Manganese ferrite nanoparticles (MnFe2O4) were synthesized via surfactant-assisted co-precipitation, where sodium dodecyl sulfate (SDS) was used as the template to control particle size at various SDS concentrations. The substitutions of iron (II) (Fe2+) into the MnFe2O4 ferrite nanoparticles were carried out to obtain Fe(1–x)MnxFe2O4, with various Mn2+: Fe2+ molar ratios. The synthesized ferrite nanoparticles were characterized by the Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), X-ray diffractometer (XRD), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), two-point probe, and vibrating sample magnetometer (VSM) techniques. The experimental Mn:Fe mole ratios of the Fe(1−x)MnxFe2O4 ferrite nanoparticles were verified to be in agreement with the theoretical values. The synthesized MnFe2O4 and Fe(1−x)MnxFe2O4 ferrite nanoparticles were of mixed spinel structures, with average spherical particle sizes between 17–22 nm, whereas the magnetite ferrite nanoparticles (Fe3O4) were of the inverse spinel structure. They showed soft ferromagnetic behavior. The synthesized Fe0.8Mn0.2Fe2O4 ferrite nanoparticle possessed the highest saturation magnetization of 88 emu/g relative to previously reported work to date.

scholarly journals Fenton Degradation of Ofloxacin Using a Montmorillonite-Fe3O4 Composite

2020 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Alamri Rahmah Dhahawi Ahmad ◽  
Saifullahi Shehu Imam ◽  
Wen Da Oh ◽  
Rohana Adnan
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Solar Irradiation ◽  
Precipitation Process ◽  
Wastewater Remediation ◽  
Solution Ph ◽  
X Ray ◽  
Subsequent Degradation ◽  
Co Precipitation

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy (FT-IR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4-montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was removed within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Moreover, the FeM-10 composite maintained high efficiency and was stable even after four continuous cycles, making it a promising candidate in real wastewater remediation.

The origin of ferromagnetism of Co-doped TiO2 nanoparticles: Experiments and theory investigation

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650296 ◽  
Author(s):  
Suyin Zhang ◽  
Zhongpo Zhou ◽  
Rui Xiong ◽  
Jing Shi ◽  
Zhihong Lu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
First Principles ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
First Principles Calculation ◽  
Ferromagnetic Behavior ◽  
X Ray ◽  
3D Electron ◽  
Co Doped

A series of Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ([Formula: see text] = 0.01, 0.03, 0.05, 0.07) nanoparticles were synthesized by sol–gel method. The X-ray diffraction, transmission electron microscopy, Raman analysis and X-ray photoelectron spectroscopy ruled out the signatures of Ti[Formula: see text], Co-clusters or any other oxides of Co. The ferromagnetic behavior was clearly observed at room temperature in doped samples with saturation magnetization [Formula: see text] of the order of 0.008–0.035 emu/g depending on doping concentrations. The saturation magnetization is found to be increased with the Co contents increasing from 1% to 7%. From the plot of the M–T curve, we obtain the [Formula: see text] as [Formula: see text][Formula: see text]515 K for 5% Co-doped TiO2. Oxygen vacancies were detected from the photoluminescence (PL) measurement. Magnetic properties analyses and PL analyses showed that oxygen vacancies probably played a major role in ferromagnetism of the Ti[Formula: see text]Co[Formula: see text]O2 system with Co substituting for Ti. The first-principles calculation was performed to investigate the magnetic properties of Co-doped TiO2 nanoparticles. It can be found that the major magnetic moment is from the 3d electron of Co. The experiment results are consistent with the first-principles calculation. The ferromagnetism derived from the spin-split of O-2p and Co-3d electron states caused by p–d orbit hybridization.

scholarly journals Fenton Degradation of Ofloxacin Using a Montmorillonite–Fe3O4 Composite

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 177
Author(s):  
Alamri Rahmah Dhahawi Ahmad ◽  
Saifullahi Shehu Imam ◽  
Wen Da Oh ◽  
Rohana Adnan
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Solar Irradiation ◽  
Precipitation Process ◽  
Solution Ph ◽  
Significant Drop ◽  
X Ray ◽  
Subsequent Degradation ◽  
Co Precipitation ◽  
Adsorption Desorption

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), a field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX), a transmission electron microscope (TEM), N2 adsorption–desorption, and Fourier transform infrared spectroscopy (FTIR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4–montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was degraded within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Although FeM composites could be a promising heterogeneous catalyst for the activation of H2O2 to degrade organic pollutants, including OFL antibiotic, the FeM-10 composite shows a significant drop in efficiency after five cycles, which indicates that more studies to improve this weakness should be conducted.

scholarly journals Size Effect on the Structural and Magnetic Properties of Nanosized PerovskiteLaFeO3Prepared by Different Methods

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Nguyen Thi Thuy ◽  
Dang Le Minh
Keyword(s):  
Magnetic Properties ◽  
Electron Microscope ◽  
Room Temperature ◽  
High Energy ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation

Nanosized LaFeO3material was prepared by 3 methods: high energy milling, citrate gel, and coprecipitation. The X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) show that the orthorhombic LaFeO3phase was well formed at a low sintering temperature of 500°C in the citrate-gel and co-precipitation methods. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations indicate that the particle size of the LaFeO3powder varies from 10 nm to 50 nm depending on the preparation method. The magnetic properties through magnetization versus temperatureM(T)and magnetization verses magnetic fieldM(H)characteristics show that the nano-LaFeO3exhibits a weak ferromagnetic behavior in the room temperature, and theM(H)curves are well fitted by Langevin functions.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

scholarly journals Preparation and Characterization of Visible-Light-Activated Fe-N Co-Doped TiO2and Its Photocatalytic Inactivation Effect on Leukemia Tumors

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kangqiang Huang ◽  
Li Chen ◽  
Jianwen Xiong ◽  
Meixiang Liao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Light Therapy ◽  
Cell Counting ◽  
Visible Absorption ◽  
X Ray ◽  
Photocatalytic Inactivation ◽  
Inactivation Efficiency ◽  
Co Doped

The Fe-N co-doped TiO2nanocomposites were synthesized by a sol-gel method and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). Then the photocatalytic inactivation of Fe-N-doped TiO2on leukemia tumors was investigated by using Cell Counting Kit-8 (CCK-8) assay. Additionally, the ultrastructural morphology and apoptotic percentage of treated cells were also studied. The experimental results showed that the growth of leukemic HL60 cells was significantly inhibited in groups treated with TiO2nanoparticles and the photocatalytic activity of Fe-N-TiO2was significantly higher than that of Fe-TiO2and N-TiO2, indicating that the photocatalytic efficiency could be effectively enhanced by the modification of Fe-N. Furthermore, when 2 wt% Fe-N-TiO2nanocomposites at a final concentration of 200 μg/mL were used, the inactivation efficiency of 78.5% was achieved after 30-minute light therapy.

Preparation of Carbon Nanofibers from Polyacrylonitrile Nanofibers by Electrospinning

2011 ◽  
Vol 415-417 ◽  
pp. 642-647
Author(s):  
En Zhong Li ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Hai Dou Wang ◽  
Bin Shi Xu
Keyword(s):  
Electron Microscope ◽  
Carbon Nanofibers ◽  
Photoelectron Spectroscopy ◽  
Solution Concentration ◽  
Dimethyl Formamide ◽  
Ultrafine Fibers ◽  
X Ray ◽  
Scanning Electron ◽  
Pan Fibers

Ultrafine fibers were electrospun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers. The effects of solution concentration, applied voltage and flow rate on preparation and morphologies of electrospun PAN fibers were investigated. Morphologies of the green fibers, stabilized fibers and carbonized fibers were compared by scanning electron microscope (SEM). The diameter of PAN nanofibers is about 450nm and the distribution of diameter is well-proportioned. Characterization of the elements changes of fibers were performed by X-ray photoelectron spectroscopy (XPS).

Template Induced Synthesis of Nano-Hydroxyapatite by Co-Precipitation Method

2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Electron Microscope ◽  
Chondroitin Sulfate ◽  
Aspartic Acid ◽  
Transmission Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Co Precipitation

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).

scholarly journals Ferromagnetic Properties of N-Doped and Undoped TiO2 Rutile Single-Crystal Wafers with Addition of Tungsten Trioxide

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1934 ◽  
Author(s):  
Jing Xu ◽  
Haiying Wang ◽  
Zhongpo Zhou ◽  
Zhaorui Zou
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Saturation Magnetization ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Tio2 Surface ◽  
Doped Tio2 ◽  
X Ray ◽  
N Doping ◽  
Tio2 Rutile

In this work, undoped, N-doped, WO3-loaded undoped, and WO3-loaded with N-doped TiO2 rutile single-crystal wafers were fabricated by direct current (DC) magnetron sputtering. N-doping into TiO2 and WO3 loading onto TiO2 surface were used to increase and decrease oxygen vacancies. Various measurements were conducted to analyze the structural and magnetic properties of the samples. X-ray diffraction results showed that the N-doping and WO3 loading did not change the phase of all samples. X-ray photoelectron spectroscopy results revealed that W element loaded onto rutile single-crystal wafers existed in the form of WO3. UV-Vis spectrometer results showed that the absorption edge of WO3-loaded undoped and WO3-loaded with N-doped TiO2 rutile single-crystal wafers had red shift, resulting in a slight decrease in the corresponding band gap. Photoluminescence spectra indicated that oxygen vacancies existed in all samples due to the postannealing atmosphere, and oxygen vacancies density increased with N-doping, while decreasing with WO3 loading onto TiO2 surface. The magnetic properties of the samples were investigated, and the saturation magnetization values were in the order N-doped > WO3-loaded with N-doped > undoped > WO3-loaded undoped rutile single-crystal wafers, which was the same order as the oxygen vacancy densities of these samples. N-doping improved the saturation magnetization values, while WO3-loaded decreased the saturation magnetization values. This paper reveals that the magnetic properties of WO3-loaded with N-doped rutile single-crystal wafers originate from oxygen vacancies.

scholarly journals Photocatalytic Degradation of Estriol Using Iron-Doped TiO2 under High and Low UV-Irradiation

2018 ◽  
Author(s):  
Irwing M. Ramírez-Sánchez ◽  
Erick R. Bandala
Keyword(s):  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Uv Irradiation ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Bet Surface Area ◽  
Doped Tio2 ◽  
X Ray ◽  
Transmission Electron ◽  
Iron Doped

Iron Doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe3+) was in the lattice of TiO2 and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radical (•OH) and estriol (E3) degradation. Fe-TiO2 materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO2 (zero-iron TiO2) and Aeroxide® TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.

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