Hydrothermal synthesis of alpha Fe 2 O 3 nanoparticles capped by Tween-80 (original) (raw)
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A novel approach for producing α- and γ-Fe 2O 3 nanoparticles in various media
International Journal of Nanoparticles, 2012
Iron (III) chloride hexahydrate (FeCl 3 .6H 2 O), glycerine, three surfactants and sodium hydroxide (NaOH) are used as the precursors for the preparation of α and γ iron oxide nanoparticles. XRD and TEM are employed to characterise the particles. Novel pathways are identified that may be used to produce either α or γ phases without changing the temperature and through changing the preparation sequence. If the as-prepared particles from the solution produced in the presence of a surfactant, are first washed and then calcinated, the α phase is obtained, whereas if the particles are first calcinated and then washed, the γ phase is produced.
Journal of Nanoparticle Research
The production of low-dimensional nanoparticles (NPs) with appropriate surface modification has attracted increasing attention in biological, biochemical, and environmental applications including chemical sensing, photocatalytic degradation, separation, and purification of toxic molecules from the matrices. In this study, iron oxide NPs have been prepared by hydrothermal method using ferric chloride and urea in aqueous medium under alkaline condition (pH 9 ~ 10). As-grown low-dimensional NPs have been characterized by UV–vis spectroscopy, FT-IR, X-ray diffraction, Field emission scanning electron microscopy, Raman spectroscopy, High-resolution Transmission electron microscopy, and Electron Diffraction System. The uniformity of the NPs size was measured by the scanning electron microscopy, while the single phase of the nanocrystalline β-Fe2O3 was characterized using powder X-ray diffraction technique. As-grown NPs were extensively applied for the photocatalytic degradation of acridin...
A Facile Method for Synthesis of α-Fe2O3 Nanoparticles and Assessment of Their Characterization
Nature, Environment and Pollution Technology/Nature, environment and pollution technology, 2024
Recently, magnetic nanomaterials have gained much attention from researchers because of their various unique physical and chemical properties and usage in a wide range of technological aspects. In this study, the synthesis of α-Fe 2 O 3 nanoparticles was performed by a simple co-precipitation method. The synthesis of α-Fe 2 O 3 nanoparticles was carried out by mixing ferric nitrate and oxalic acid in an aqueous solution followed by evaporation, resulting in the solution's dried form. The synthesized nanoparticles were analyzed by XRD, FTIR, Raman spectra, SEM-EDX, DSC, BET, and Zeta potential for detailed examination of the morphology, structure, and other physicochemical characteristics. The XRD results confirmed that the nanoparticles formed were Hematite (α-Fe 2 O 3) after the evaluation of obtained spectra compared to the Joint Committee on Powder Diffraction Standards Database (JCPDS). The FTIR spectra showed various bonds among functional groups, O-H bending, Fe-O group, and within-vibration bonds. The phase study of the α-Fe 2 O 3 nanoparticles was performed by using Raman spectroscopy. SEM depicted a sphere-like or rhombohedral (hexagonal) structure, and the EDX spectrum confirmed the peaks of iron and oxygen.
SN Applied Sciences
Antimicrobial ɑ-Fe 2 O 3 nanoparticles were synthesized using hydrothermal method (HS) at 150 °C for 12 h. FeCl 3 and urea were used to have ɑ-Fe 2 O 3 nanostructures with the help of appropriate amount of surfactants to control the morphology. Stable colloidal suspensions were prepared using synthesized nanoparticles and then 3-D metallic filters were coated using electrophoretic deposition under definite voltage and time. It was shown that the obtained particles were effective to eliminate S. Aureus Bacterias.
Magnetic properties of α-Fe2O3 nanoparticle synthesized by a new hydrothermal method
Journal of Magnetism and Magnetic Materials, 2005
Nanoparticles of a-Fe 2 O 3 have been prepared using a hydrothermal synthesis method in aqueous-organic microemulsion under mild alkaline condition. The condensation reaction was optimized in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB). It was found that the size and nature of the a-Fe 2 O 3 nanoparticle strongly depends on the pH, oxalic acid and CTAB as well as tetramethylammonium hydroxide (TMAOH, alkali source) concentrations. The uniformity of the particle size was checked by the transmission electron microscopy while the single phase of the nanocrystalline a-Fe 2 O 3 was characterized using powder X-ray diffraction. The Mo¨ssbauer study exhibited a sextet pattern with internal field smaller than that of the bulk counterpart. The temperature variation of magnetization showed a broad maximum at around 125 K while the field-cooled effect of the magnetization showed the branching between the field cooled and zero field cooled magnetization up to 340 K. A large anisotropy has been observed from the analysis of magnetization curve as well as from the large blocking temperature. The estimation of the particle size from the magnetization curve was found to be in close agreement with the TEM results.
Applied Physics A
α-Fe 2 O 3 nanoparticles were synthesized using ferric chloride (FeCl 3 •9H 2 O), ferrous chloride (FeCl 2 •6H 2 O), and sodium hydroxide (NaOH) via simple co-precipitation method in the absence and presence of four separate and commonly used surfactants such as cetyltrimethylammonium bromide (CTAB,) polyvinylpyrrolidone K25, polyvinyl alcohol, and ethylenediaminetetraacetic acid. The aim of this study is to see whether different surfactants have an effect on the morphological, structural, optical, and magnetic properties of iron oxide nanoparticles. The X-ray diffraction data confirmed rhombohedral crystallographic structure for α-Fe 2 O 3 sample. The average crystallite size for synthesized nanoparticles using the coprecipitation method with (and without) surfactant was calculated to be ∼ 15 ± 4.7 nm to 20 ± 1.2 nm. The transmission electron microscopy studies revealed spherical and some rod-like morphology of nanoparticles prepared with (and without) surfactant. Surfactant-assisted α-Fe 2 O 3 nanoparticles showed a blue shift in optical absorption spectra due to the quantum confinement effect. The functional properties of nanoparticles are unaffected by the surfactant. At room temperature, all samples had a magnetization curve that was typical of ferromagnetic behavior, with the exception of α-Fe 2 O 3 nanoparticles prepared with CTAB surfactant, which had almost superparamagnetic behavior. Keywords X-ray diffraction (XRD) • Infrared (IR) spectroscopy • Magnetic properties • Optical properties • Morphology • α-Fe 2 O 3 nanoparticles * Pratishtha Kushwaha
Surfactant-Assisted Combustion Method for the Synthesis of α-Fe 2 O 3 Nanocrystalline Powders
In this present work, a new surfactant-assisted combustion method has been performed to synthesize α-Fe2O3 powders by using iron nitrate as an oxidizer, glycine as a fuel and TWEEN 80 as a non-ionic surfactant. The effects of the fuel at different molar ratios assisted with surfactant are investigated with XRD, DT/TGA, UV-Vis Spectroscopy, FT-IR and SEM techniques. The investigation range of molar ratios of oxidizer is 0.1M; fuels are of molar ratios 0.1M, 0.15M, 0.2M, 0.25M and 0.3M and with surfactant ratio 0.07M have been studied. Structural characterization of different samples is investigated by X-ray Diffractometer. From X-ray Diffraction data lattice parameters, crystallite sizes, micro strains, cell volumes and porosities of the samples are calculated. The average crystallite sizes of the samples are obtained by Debye-Schererr's formula and Williamson-Hall plot. The XRD result also indicates rhombohedral system (R3c) with lattice parameters a=5.035Ao and c= 13.748Ao with the JCPDS data card no: 33-0664. Thermal studies of the samples are analyzed by TG/DTA analysis. Particle size distributions were observed by Particle size analyzer. Surface morphology of the samples is studied by scanning electron microscopy.
A Simple and Effective Method of the Synthesis of Nanosized Fe 2 O 3 particles
Nanosized Iron oxide is prepared by using precipitation method from iron nitrate and liquid ammonia. Thermal analysis shows that synthesized iron oxide shows some weight loss and oxide undergoing decomposition, dehydration or any physical change from TGA curve we observe that Iron oxide shows stable weight loss above 400 0 C. In DTA curve also, there is exothermic and endothermic peak. Which shows phase transition, solid state reaction or any chemical reaction occurred during heating treatment. Morphology is observed by scanning electron microscopy (SEM) shows particles are nanosized. Further morphology observation by Transmission Electron Microscopy (TEM) revels that Iron Oxide has the corundum (Al 2 O 3 ) structure. Magnetic measurements shows that iron oxide has five unpaired electron and strongly paramagnetic character.
Basic and Applied Sciences - Scientific Journal of King Faisal University
The current study focuses on a dual aim of developing an easy method to synthesise monodisperse hematite iron oxide (α-Fe 2 O 3) nanoparticles and controlling their optical, structural and morphological properties. By using a low-cost and eco-friendly room temperature sonication method, a series of iron oxide nanoparticles were prepared on a nano scale, with fine sizes ranging from 4-10 nm. Optical, structural and morphological properties were precisely modified by varying the concentration of the solution of iron chloride (0.01 M, 0.02 M and 0.05 M). X-ray diffraction and Raman spectra revealed that the prepared nanoparticles had a high crystallinity, confirming that they were hematite. The nanoparticles' crystallite sizes increased from 6 to 10 nm with solution molarity. The optical measurements showed that the band gap energy of α-Fe 2 O 3 nanoparticles (annealed) decreased from 2.67 eV to 2.46 eV with the increasing of solution molarity from 0.01 M to 0.05 M, respectively. Results of field emission scanning electron microscopy demonstrated that the α-Fe 2 O 3 nanoparticles appeared as spherical dots, and their sizes increased from 6 to 10 nm with the concentration of the solution. The presented green synthesis might be useful in controlling the functional properties of magnetic nanostructures for a variety of applications.
Hydrothermal synthesis and structural characterization of (1− x)α-Fe 2O 3– xSnO 2 nanoparticles
Journal of Physics and Chemistry of Solids, 2004
Structural and morphological characteristics of (1−x)α-Fe2O3–xSnO2 (x=0.0–1.0) nanoparticles obtained under hydrothermal conditions have been investigated by X-ray diffraction (XRD), transmission Mössbauer spectroscopy, scanning and transmission electron microscopy as well as energy dispersive X-ray analysis. On the basis of the Rietveld structure refinements of the XRD spectra at low tin concentrations, it was found that Sn4+ ions partially substitute for Fe3+ at the octahedral sites and also occupy the interstitial octahedral sites which are vacant in α-Fe2O3 corundum structure. A phase separation of α-Fe2O3 and SnO2 was observed for x≥0.4: the α-Fe2O3 structure containing tin decreases simultaneously with the increase of the SnO2 phase containing substitutional iron ions. The mean particle dimension decreases from 70 to 6 nm, as the molar fraction x increases up to x=1.0. The estimated solubility limits in the nanoparticle system (1−x)α-Fe2O3–xSnO2 synthesized under hydrothermal conditions are: x≤0.2 for Sn4+ in α-Fe2O3 and x≥0.7 for Fe3+ in SnO2.