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Journal ArticleDOI

Control of the shape and size of iron oxide (α-Fe2O3) nanoparticles synthesized through the chemical precipitation method

01 Jan 2017-Results in physics (Elsevier)-Vol. 7, pp 3007-3015
TL;DR: In this paper, the impact of varying the concentration of precursor on the crystalline phase, size, and morphology of α-Fe 2 O 3 products was explored by X-ray diffraction (XRD), transmission electron microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FT-IR) spectroscopy, Differential Thermal Analysis (DTA), Thermo Gravimetric Analysis (TGA), Ultraviolet-Visible (UV-Vis) analysis and Photoluminescence (PL).
Abstract: Hematite (α-Fe 2 O 3 ) nanoparticles were synthesized via a simple chemical precipitation method. The impact of varying the concentration of precursor on the crystalline phase, size and morphology of α-Fe 2 O 3 products was explored. The characteristic of the synthesized hematite nanoparticles were evaluated by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FT-IR) spectroscopy, Raman spectroscopy, Differential Thermal Analysis (DTA), Thermo Gravimetric Analysis (TGA), Ultraviolet–Visible (UV–Vis) analysis and Photoluminescence (PL). XRD data revealed a rhombohedral (hexagonal) structure with the space group R -3 c in all samples. Uniform spherical like morphology was confirmed by TEM and SEM. The result revealed that the particle sizes were varied between 21 and 82 nm and that the increase in precursor concentration (FeCl 3 , 6H 2 O) is accompanied by an increase in the particle size of 21 nm for pure α-Fe 2 O 3 synthesized with [Fe 3+ ] = 0.05 M at 82 nm for pure α-Fe 2 O 3 synthesized with [Fe 3+ ] = 0.4 M. FT-IR confirms the phase purity of the nanoparticles synthesized. The Raman spectroscopy was used not only to prove that we have synthesized pure hematite but also to identify their phonon modes. The thermal behavior of compound was studied by using TGA/DTA results: The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. Besides, the optical investigation revealed that samples have an optical gap of about 2.1 eV and that this value varies as a function of the precursor concentration.
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Journal ArticleDOI
TL;DR: The close link between physicochemical properties and magnetic characterization is described, essential to developing innovative and powerful magnetic-driven nanocarriers for Central Nervous System disorders.
Abstract: Magnetic Nanoparticles (MNPs) are of great interest in biomedicine, due to their wide range of applications. During recent years, one of the most challenging goals is the development of new strategies to finely tune the unique properties of MNPs, in order to improve their effectiveness in the biomedical field. This review provides an up-to-date overview of the methods of synthesis and functionalization of MNPs focusing on Iron Oxide Nanoparticles (IONPs). Firstly, synthesis strategies for fabricating IONPs of different composition, sizes, shapes, and structures are outlined. We describe the close link between physicochemical properties and magnetic characterization, essential to developing innovative and powerful magnetic-driven nanocarriers. In conclusion, we provide a complete background of IONPs functionalization, safety, and applications for the treatment of Central Nervous System disorders.

149 citations

Journal ArticleDOI
TL;DR: In this article, the size, structural, optical and magnetic properties were determined and compared using X-ray diffraction (XRD), transmission electron microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FT-IR), Raman spectroscopy, Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), Ultraviolet-Visible (UV-Vis) analysis, Superconducting QUantum Interference Device (SQUID) magnetometer and Photolumines
Abstract: In this work the iron oxide (α-Fe 2O3 ) nanoparticles are synthesized using two different methods: precipitation and hydrothermal. Size, structural, optical and magnetic properties were determined and compared using X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FT-IR), Raman spectroscopy , Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), Ultraviolet–Visible (UV–Vis) analysis, Superconducting QUantum Interference Device (SQUID) magnetometer and Photoluminescence (PL). XRD data further revealed a rhombohedral (hexagonal) structure with the space group (R-3c) and showed an average size of 21 nm for hydrothermal samples and 33 nm for precipitation samples which concorded with TEM and SEM images. FT-IR confirms the phase purity of the nanoparticles synthesized. The Raman spectroscopy was used not only to prove that we have synthesized pure α-Fe 2O3 but also to identify their phonon modes. The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. The decrease in the particle size of hematite of 33 nm for precipitation samples to 21 nm for hydrothermal samples is responsible for increasing the optical band gap of 1.94–2.10 eV where, the relation between them is inverse relationship. The products exhibited the attractive magnetic properties with good saturation magnetization , which were examined by a SQUID magnetometer. Photoluminescence measurements showed a strong emission band at 450 nm. Pure hematite prepared by hydrothermal method has smallest size, best crystallinity , highest band gap and best value of saturation magnetization compared to the hematite elaborated by the precipitation method.

118 citations

Journal ArticleDOI
TL;DR: In this article, the effects of precursor concentrations, from 0.05 to 0.45 µm, on the product size, morphology, crystallinity, and lumps formation were reported.
Abstract: Pure hematite nanoparticles (HNPs) were successfully synthesized via the simple precipitation route by using ferric sulfate precursor and ammonium hydroxide (NH4OH) precipitant. The current study reports the effects of precursor concentrations, from 0.05 to 0.45 M, on the product size, morphology, crystallinity, and lumps formation. X-ray diffraction (XRD) data confirmed the synthesis of pristine HNPs having a rhombohedrally centered hexagonal structure. In addition, the particle size effect on the XRD peak shifting was studied and found to be consistent with the calculated size results by Scherer equation. Transmission electron microscopy revealed mixed polygonal and hexagonal morphologies with an average size of (16–44 nm) depending on the precursor concentration. Scanning electron microscopy depicts lots of agglomerations and lumps with increasing the precursor concentration. Raman spectra not only show the seven phonon modes of pristine hematite phase but also confirm the evolution of the crystal structure with concentration. Thermal analyses proved that the synthesized α-Fe2O3 products in the current work using 0.05 M precursor concentration are well crystallized at around ≈464 °C. Thus, current work presents smaller-sized HNPs crystallized at lower temperature ranges with different morphologies and higher probable vulnerable facets compared to previous studies. This will show improved properties and give rise to higher potentials for various applications. Furthermore, it verifies that the precursor nature is the key factor affecting both size and morphology, whereas, precursor concentration not only affects the particle size as reported previously but also crystallinity, morphology development, and lumps formation of the final product.

115 citations

Journal ArticleDOI
01 Jan 2021
TL;DR: In this article, the authors evaluated the efficacy of green synthesized iron oxide (α-Fe2O3) and magnesium oxide (MgO) nanoparticles (NPs) for wastewater treatment of crude textile and tannery effluents.
Abstract: The textile and leather industry produces large amounts of wastewater that contains high levels of chemicals and other pollutants, incorporated during the processing stages We evaluated the efficacy of green synthesized iron oxide (α-Fe2O3) and magnesium oxide (MgO) nanoparticles (NPs) for wastewater treatment of crude textile and tannery effluents Green synthesis of α-Fe2O3-NPs and MgO-NPs was conducted using the newly obtained Aspergillus carbonarious strain D-1 The optimization of the physicochemical parameters for the biosynthesis of NPs, including incubation periods, contact time, pH, temperature, and precursor concentrations, were assessed The characterization of NPs obtained under optimal conditions was evaluated using UV–visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, dynamic light scattering (DLS), and Fourier Transform Infrared (FT-IR) Spectroscopy The optimal concentration for efficient textile/tannery wastewater decolorization was determined to be 100 mg NPs after eight hours for α-Fe2O3-NPs and after four hours for MgO-NPs Under these conditions, chemical oxygen deman (COD), pH value, total dissolved solids (TDS), total suspended solids (TSS), and conductivity were greatly reduced as compared to control for crude textile wastewater GC–MS analysis of NPs-treated textile wastewater revealed that some major compounds were greatly diminished, bio-transformed, or completely degraded MgO and α-Fe2O3 NPs exhibited a high capacity to reduce the COD of tannery wastewater by 975% and 950%, respectively Hematite NPs exhibited higher removal capacity for TDS, TSS, and conductivity compared to MgO-NPs MgO and hematite NPs exhibited high capacities to remove Cr, with MgO redcing Cr by 8706 and hematite NPs reducing Cr by 754% MgO-NPs were more effective than α-Fe2O3-NPs at removing Pb, Ni, and Cd

72 citations

Journal ArticleDOI
TL;DR: The surface modification and functionalization approaches presented lately in the scientific literature for improving or modulating magnetite nanoparticles for their applications in nanomedicine are summarized.
Abstract: Functionalization of nanomaterials can enhance and modulate their properties and behaviour, enabling characteristics suitable for medical applications. Magnetite (Fe3O4) nanoparticles are one of the most popular types of nanomaterials used in this field, and many technologies being already translated in clinical practice. This article makes a summary of the surface modification and functionalization approaches presented lately in the scientific literature for improving or modulating magnetite nanoparticles for their applications in nanomedicine.

70 citations


Cites background from "Control of the shape and size of ir..."

  • ...1 Fe3+/Fe2+ ratio Iron oxide phase Directly proportional [37]...

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References
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Book
01 Jan 1971
TL;DR: Optical processes in semiconductors as mentioned in this paper, Optical Process in Semiconductors (OPP), Optical Process of Semiconductor (OPS) and Optical Process (OPI)
Abstract: Optical processes in semiconductors , Optical processes in semiconductors , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

4,630 citations

Journal ArticleDOI
TL;DR: In this paper, the laser power dependence of the spectra of oxides and oxyhydroxides was investigated by using Raman microscopy, and it was shown that increasing laser power causes the characteristic bands of hematite to show up in the spectrum of most of the compounds studied.
Abstract: Hematite (α-Fe2O3), magnetite (Fe3O4), wustite (FeO), maghemite (γ-Fe2O3), goethite (α-FeOOH), lepidocrocite (γ-FeOOH) and δ-FeOOH were studied by Raman microscopy. Such compounds have already been studied by Raman spectroscopy, but there are some disagreements in the reported data. Here, Raman microscopy was employed to investigate the laser power dependence of the spectra of these oxides and oxyhydroxides. Low laser power was used for the reference spectra in order to minimize the risks of spectral changes due to sample degradation. The results obtained show that increasing laser power causes the characteristic bands of hematite to show up in the spectra of most of the compounds studied whereas the hematite spectrum undergoes band broadening and band shifts. © 1997 John Wiley & Sons, Ltd.

2,569 citations


"Control of the shape and size of ir..." refers background in this paper

  • ...Pure hematite belongs to the R-3c crystal space group and seven phonon lines are expected to appear in the Raman spectrum, namely two A1g phonon modes and five Eg phonon modes [38]....

    [...]

Journal ArticleDOI
TL;DR: In this article, thin films of silicon-doped Fe2O3 were deposited by APCVD (atmospheric pressure chemical vapor deposition) from Fe(CO)5 and TEOS (tetraethoxysilane) on SnO2-coated glass at 415 °C.
Abstract: Thin films of silicon-doped Fe2O3 were deposited by APCVD (atmospheric pressure chemical vapor deposition) from Fe(CO)5 and TEOS (tetraethoxysilane) on SnO2-coated glass at 415 °C. HRSEM reveals a highly developed dendritic nanostructure of 500 nm thickness having a feature size of only 10−20 nm at the surface. Real surface area determination by dye adsorption yields a roughness factor of 21. XRD shows the films to be pure hematite with strong preferential orientation of the [110] axis vertical to the substrate, induced by silicon doping. Under illumination in 1 M NaOH, water is oxidized at the Fe2O3 electrode with higher efficiency (IPCE = 42% at 370 nm and 2.2 mA/cm2 in AM 1.5 G sunlight of 1000 W/m2 at 1.23 VRHE) than at the best reported single crystalline Fe2O3 electrodes. This unprecedented efficiency is in part attributed to the dendritic nanostructure which minimizes the distance photogenerated holes have to diffuse to reach the Fe2O3/electrolyte interface while still allowing efficient light abso...

1,442 citations


"Control of the shape and size of ir..." refers background in this paper

  • ...The synthesis of hematite particles (a-Fe2O3) of different sizes and shapes was thoroughly examined because their new chemical and physical properties compared to bulk materials, and their potential applications in inorganic pigments [1], catalysts [2], gas and humidity sensors [3,4], photoanode for photoelectrochemical cells [5], photoelectrolysis reactors [6], water treatment [7], and lithium ion batteries [8]....

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Journal ArticleDOI
TL;DR: In this article, the properties, applications, and syntheses of three magnetic iron oxides (hematite, magnetite, and maghemite) are discussed and methods of preparation that allow control over the size, morphology, surface treatment and magnetic properties of their nanoparticles.

1,206 citations