Optical Properties and Applications of Hematite (α‐Fe<sub>2</sub>O<sub>3</sub>) Nanostructures

Ling, Yichuan; Wheeler, Damon A.; Zhang, Jin Z.; Li, Yat

doi:10.1002/9781118310342.ch8

Cited by 6 publications

(5 citation statements)

References 101 publications

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“…This is because the distance between the dopant (activator) and the array goes up. The spinel ferrite shows a strong band of luminescence located at 460 nm (2.8 eV); this luminescence can be observed even with the naked eye at room temperature and is due to exciton emission 19 . Calcination of spinel ferrite increases the PL intensity due to an increase in the population of carriers.…”

Section: Resultsmentioning

confidence: 99%

“…Photoluminescence (PL) is one of the more interesting applications. The most powerful Photoluminescence spectra are created by direct recombination of photo-generated holes formed in the tetrahedral and octahedral sites of the crystals, oxygen vacancies trapping electrons, and the electronic transitions in Fe +3 ions from the 3d 5 state to the 3d 4 4 s state 19 .…”

Section: Introductionmentioning

confidence: 99%

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Influence of sintering temperature on structural and optical properties of Cd0.5Cu0.5CrxFe2−xO4 ferrites

El shater,

Awad,

Abdel-Khalek

et al. 2023

Sci Rep

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Two ferrite series were synthesized. One series has nanosize samples that have been prepared by the co-precipitation method, and the second series has the corresponding bulk samples that have been sintered at 1000 °C for 6 h. X-ray diffraction has been used to estimate the cubic spinel structure of both series. The crystallite size, theoretical density, and porosity of the nanomaterials are larger than those of the bulk materials. HRTEM analysis demonstrated the aggregation of nanoscale samples, including an average particle size of 9–22.5 nm. However, bulk specimens have a limited surface area. The agglomeration of the nanoparticles was seen in TEM images, in which the mean particle size was within the limit of the crystallite size (R) result and ranged from 14 to 20 nm. The appearance of the spinel phase in the samples was validated through Raman spectroscopy. Different cation occupation ratios in either tetrahedral or octahedral sites have been identified to be associated with an observable systematic shift and asymmetric flattening in Raman spectra with a variation in Cr3+ concentration. The optical characterization was performed using the UV/Vis methodology, and the results reveal that the absorption cutoff frequency declines as the chromium content rises. It was also estimated that the optical bandgap averaged 3.6 eV for nanosamples and 4.6 eV for overall bulk materials. The highest photoluminescence emission was seen at wavelengths between λem = 415 and 460 nm. The photoluminescence emission peaks of both bulk and nanoscale materials were red-shifted. These results accurately reflect the corresponding energy gap values for almost the same ranges. Sintering leads to a rise in photoluminescence.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of sintering temperature on structural and optical properties of Cd0.5Cu0.5CrxFe2−xO4 ferrites

El shater,

Awad,

Abdel-Khalek

et al. 2023

Sci Rep

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“…Due to its stability, inertness, biocompatibility and less toxicity, α-Fe 2 O 3 was suitable material for drug delivery, cell conjugates, imaging, and gene therapy. Various physical and chemical techniques such as sol-gel, sono-chemical, ball milling, co-precipitation, hydrothermal and chemical precipitation methods have been developed and used to synthesise α-Fe 2 O 3 nanoparticles [5]. Moreover, because of its low electronic conductivity, low magnetic properties and electronic conductivity, α-Fe 2 O 3 was unavoidably affected by this reason.…”

Section: Introductionmentioning

confidence: 99%

Biological synthesis, physico-chemical characterization of undoped and Co doped α-Fe₂O₃ nanoparticles using Tribulus terrestris leaf extract and its antidiabetic, antimicrobial applications

Athithan¹,

Jeyasundari²,

Jacob³

2021

Adv. Nat. Sci: Nanosci. Nanotechnol.

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Hematite (α-Fe2O3) nanoparticles (NPs) were chemically and thermodynamically more stable among iron oxide nanoparticles. Doping of Co2+ metal ion in α-Fe2O3 can modify the structural, optical and magnetic properties of NPs and also enhances the potential of the biomedical applications. In the current study, undoped and Co doped hematite nanoparticles were synthesised by co-precipitation method using Tribulus terrestris L. leaf extract as bio-reductant. The magnetic, optical and structural investigations were studied with the help of Ultraviolet-visible (UV-Vis), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy equipped with Energy Dispersive X-ray (SEM-EDX) Spectroscopy, Vibrating Sample Magnetometer (VSM) and X-ray Diffraction (XRD) Spectroscopy. XRD analysis shows that synthesized nanoparticles were in hematite phase, rhombohedral in structure. XRD spectral pattern clearly evidenced that prepared α-Fe2O3 and Co-Fe2O3 NPs were highly crystalline with no impurity peaks. Using VSM spectra, the M-H curve indicates that saturation magnetisation (Ms) value increases for Co-Fe2O3 NPs than undoped α-Fe2O3 NPs, it can be clearly seen that doping largely affects the magnetic nature of nanoparticles. In the UV-Vis spectra, absorption maxima increases and band gap value decreases for cobalt doped hematite nanoparticles indicating the substitution of Fe2+ ions by Co2+ ions in α-Fe2O3 lattice sites. Antidiabetic and antimicrobial activity of the synthesized undoped and Co doped hematite NPs were tested by alpha-amylase inhibitory and disc diffusion method. The Co-Fe2O3 NPs have greatly inhibited the digestive enzyme and microbial strains as compared to undoped α-Fe2O3 NPs.

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“…[7, 8]. Based on these applications different physical and chemicals techniques such as sono-chemical, co-precipitation, sol-gel and others have been developed and employed to synthesize the NPs [9]. These synthesis process sometimes include the use of hazardous chemicals and/or generation of hazardous by-products [10, 11].…”

Section: Introductionmentioning

confidence: 99%

A green approach for the synthesis of α-Fe2O3 nanoparticles from Gardenia resinifera plant and it's In vitro hyperthermia application

Karade

Parit

Dawkar

et al. 2019

Heliyon

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The Gardenia , traditional medicinal plant used from ancient time to increase appetite and other medicinal uses has been employed for the synthesis of superparamagnetic α-Fe 2 O 3 nanoparticles (NPs). The plant extracts unveiled its bifunctional nature through the reducing ferric ions by phenolic groups and capping nature through the –OH bonding over the NPs surface. The prepared NPs exhibits α-Fe 2 O 3 phase among iron oxides and spherical morphology with an average size around 5 nm. The magnetic measurements proved the superparamagnetic behavior of NPs with non-saturating M S value of 8.5 emu/g at room temperature (300 K). Further, the hyperthermia study reveals, the NPs achieved a temperature of 40 °C and 43 °C within 6 min and reaches up to 43 °C and 45 °C within 10 min only for 5 μg/mL and 10 μg/mL concentrations respectively. Based on the heating profile of NPs, the SAR values (167.7 Oe, 300 MHz) calculated and are found to be around 62.75 W/g and 24.38 W/g for 5 μg/mL and 10 μg/mL NPs concentrations respectively. Subsequently, these have been used for toxicity assays, which presented enhanced cytotoxic effects on human mesenchymal cells lines proving them as a potential candidate for the biomedical applications.

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Optical Properties and Applications of Hematite (α‐Fe₂O₃) Nanostructures

Cited by 6 publications

References 101 publications

Influence of sintering temperature on structural and optical properties of Cd0.5Cu0.5CrxFe2−xO4 ferrites

Influence of sintering temperature on structural and optical properties of Cd0.5Cu0.5CrxFe2−xO4 ferrites

Biological synthesis, physico-chemical characterization of undoped and Co doped α-Fe₂O₃ nanoparticles using Tribulus terrestris leaf extract and its antidiabetic, antimicrobial applications

A green approach for the synthesis of α-Fe2O3 nanoparticles from Gardenia resinifera plant and it's In vitro hyperthermia application

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Optical Properties and Applications of Hematite (α‐Fe2O3) Nanostructures

Cited by 6 publications

References 101 publications

Influence of sintering temperature on structural and optical properties of Cd0.5Cu0.5CrxFe2−xO4 ferrites

Influence of sintering temperature on structural and optical properties of Cd0.5Cu0.5CrxFe2−xO4 ferrites

Biological synthesis, physico-chemical characterization of undoped and Co doped α-Fe2O3 nanoparticles using Tribulus terrestris leaf extract and its antidiabetic, antimicrobial applications

A green approach for the synthesis of α-Fe2O3 nanoparticles from Gardenia resinifera plant and it's In vitro hyperthermia application

Contact Info

Product

Resources

About

Optical Properties and Applications of Hematite (α‐Fe₂O₃) Nanostructures

Biological synthesis, physico-chemical characterization of undoped and Co doped α-Fe₂O₃ nanoparticles using Tribulus terrestris leaf extract and its antidiabetic, antimicrobial applications