A facile low temperature method for the synthesis of CoFe<sub>2</sub>O<sub>4</sub> nanoparticles possessing excellent microwave absorption properties

Moitra, Debabrata; Hazra, Subhenjit; Ghosh, B.; Jani, Raj Kumar; Patra, Manoj Kumar; Vadera, Sampat Raj; Ghosh, Narendra Nath

doi:10.1039/c5ra06600j

Cited by 36 publications

(15 citation statements)

References 53 publications

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“…The applicative potential of ferrite nanoparticles (NPs) is enormous in various technological fields such as permanent magnets [1], biomedicine [2], catalysis [3], electromagnetic shielding [4], electronic devices [5], magnetic nanofluids (heat transfer [6], magnetorheology [7]), anti-pollution agents [8], building industry [9], electrochemical energy storage [10], and biosensors [11].…”

Section: Introductionmentioning

confidence: 99%

Mesoporous Cobalt Ferrite Nanosystems Obtained by Surfactant-Assisted Hydrothermal Method: Tuning Morpho-structural and Magnetic Properties via pH-Variation

et al. 2020

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A facile and cheap surfactant-assisted hydrothermal method was used to prepare mesoporous cobalt ferrite nanosystems with BET surface area up to 151 m 2 /g. These mesostructures with high BET surface areas and pore sizes are made from assemblies of nanoparticles (NPs) with average sizes between 7.8 and 9.6 nm depending on the initial pH conditions. The pH proved to be the key factor for controlling not only NP size, but also the phase purity and the porosity properties of the mesostructures. At pH values lower than 7, a parasite hematite phase begins to form. The sample obtained at pH = 7.3 has magnetization at saturation M s = 38 emu/g at 300 K (54.3 emu/g at 10 K) and BET surface area S BET = 151 m 2 /g, whereas the one obtained at pH = 8.3 has M s = 68 emu/g at 300 K (83.6 emu/g at 10 K) and S BET = 101 m 2 /g. The magnetic coercive field values at 10 K are high at up to 12,780 Oe, with a maximum coercive field reached for the sample obtained at pH = 8.3. Decreased magnetic performances are obtained at pH values higher than 9. The iron occupancies of the tetrahedral and octahedral sites belonging to the cobalt ferrite spinel structure were extracted through decomposition of the Mössbauer patterns in spectral components. The magnetic anisotropy constants of the investigated NPs were estimated from the temperature dependence of the hyperfine magnetic field. Taking into consideration the high values of BET surface area and the magnetic anisotropy constants as well as the significant magnetizations for saturation at ambient temperature, and the fact that all parameters can be adjusted through the initial pH conditions, these materials are very promising as recyclable anti-polluting agents, magnetically separable catalysts, and targeted drug delivery vehicles.

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Section: Introductionmentioning

confidence: 99%

Mesoporous Cobalt Ferrite Nanosystems Obtained by Surfactant-Assisted Hydrothermal Method: Tuning Morpho-structural and Magnetic Properties via pH-Variation

et al. 2020

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“…Magnetic cobalt ferrite nanoparticles were prepared by the co‐preparation method. [ 39 ] A mixture of COCl 2 .6H 2 O (5 mmol, 1.8 g) and FeCl 3 .6H 2 O (10 mmol, 2.7 g) in 50 ml of deionized water (in a round‐bottomed flask) was stirred at room temperature for 10 min. The pH of the reaction mixture was adjusted to 11–12 with NaOH (0.3 M) solution.…”

Section: Methodsmentioning

confidence: 99%

Zinc(II)‐poly(urea‐formaldehyde) supported on magnetic nanoparticles: A hybrid nanocatalyst for green synthesis of spiropyrans, spiroxanthenes, and spiropyrimidines

Bodaghifard

Mousavi

2020

Applied Organom Chemis

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Immobilization of metal ions onto inorganic supports has very interesting biological, industrial, and catalysis applications. In this study, CoFe2O4@SiO2@PUF@Zn(OAc)2 nanostructure was successfully fabricated by immobilization of zinc acetate on the surface of poly(urea‐formaldehyde) supported on magnetic CoFe2O4@SiO2 nanoparticles through a layer‐by‐layer assembly. The structure of hybrid nanoparticles was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, energy‐dispersive X‐ray spectroscopy, inductively coupled plasma atomic emission spectroscopy, vibrating sample magnetometry, Brunauer–Emmett–Teller surface area analysis, scanning electron microscopy, and transmission electron microscopy. Zinc‐poly(urea‐formaldehyde) supported on magnetic nanoparticles (MNPs@SiO2@PUF@Zn) was successfully used for the synthesis of spirooxindolopyran and spirooxindoloxanthene derivatives in aqueous medium as an environmentally benign condition. High yields, short reaction times, green solvent, reusability without significant reduction in catalytic activity, and simple separation of the catalyst using an external magnet along with environmental compatibility are some benefits of this procedure.

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“…CoFe 2 O 4 @SiO 2 ‐SO 3 H nanocatalyst was synthesized using a three‐step methodology (Scheme ). First, CoFe 2 O 4 magnetic nanoparticles (MNPs) were prepared following a previously reported co‐precipitation method . Second, CoFe 2 O 4 @SiO 2 was prepared by hydrolysis of tetraethyl orthosilicate (TEOS) onto the surface of the CoFe 2 O 4 MNPs in the presence of NH 3 liquor.…”

Section: Methodsmentioning

confidence: 99%

Expeditious synthesis of diverse spiro fused quinoxaline derivatives using magnetically separable core–shell CoFe₂O₄@SiO₂‐SO₃H nanocatalyst under ultrasonication

Mandal

Hazra

Sarkar

et al. 2019

Applied Organom Chemis

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A magnetically separable core–shell CoFe2O4@SiO2‐SO3H nanocatalyst has been successfully exploited as a heterogeneous acid catalyst in the synthesis of diversely substituted biologically important spiro fused pyrrolo/indolo[1,2‐a]quinoxaline derivatives through the condensation of N‐(2‐aminophenyl)pyrroles/indoles and various cyclic conjugated 1,2‐diones in ethanol under ultrasonic irradiation. Room temperature synthesis, short reaction time, wide substrate scope, good to excellent yield of products and use of a magnetically separable and recyclable nanocatalyst make this method attractive and practicable.

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A facile low temperature method for the synthesis of CoFe₂O₄ nanoparticles possessing excellent microwave absorption properties

Abstract: CoFe2O4 nanoparticles, synthesized via a co-precipitation method at 120 °C, exhibited excellent microwave absorption properties, with minimum reflection loss of −55 dB (∼99.99%) at 9.25 GHz.

Cited by 36 publications

References 53 publications

Mesoporous Cobalt Ferrite Nanosystems Obtained by Surfactant-Assisted Hydrothermal Method: Tuning Morpho-structural and Magnetic Properties via pH-Variation

Mesoporous Cobalt Ferrite Nanosystems Obtained by Surfactant-Assisted Hydrothermal Method: Tuning Morpho-structural and Magnetic Properties via pH-Variation

Zinc(II)‐poly(urea‐formaldehyde) supported on magnetic nanoparticles: A hybrid nanocatalyst for green synthesis of spiropyrans, spiroxanthenes, and spiropyrimidines

Expeditious synthesis of diverse spiro fused quinoxaline derivatives using magnetically separable core–shell CoFe₂O₄@SiO₂‐SO₃H nanocatalyst under ultrasonication

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A facile low temperature method for the synthesis of CoFe2O4 nanoparticles possessing excellent microwave absorption properties

Abstract: CoFe2O4 nanoparticles, synthesized via a co-precipitation method at 120 °C, exhibited excellent microwave absorption properties, with minimum reflection loss of −55 dB (∼99.99%) at 9.25 GHz.

Cited by 36 publications

References 53 publications

Mesoporous Cobalt Ferrite Nanosystems Obtained by Surfactant-Assisted Hydrothermal Method: Tuning Morpho-structural and Magnetic Properties via pH-Variation

Mesoporous Cobalt Ferrite Nanosystems Obtained by Surfactant-Assisted Hydrothermal Method: Tuning Morpho-structural and Magnetic Properties via pH-Variation

Zinc(II)‐poly(urea‐formaldehyde) supported on magnetic nanoparticles: A hybrid nanocatalyst for green synthesis of spiropyrans, spiroxanthenes, and spiropyrimidines

Expeditious synthesis of diverse spiro fused quinoxaline derivatives using magnetically separable core–shell CoFe2O4@SiO2‐SO3H nanocatalyst under ultrasonication

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A facile low temperature method for the synthesis of CoFe₂O₄ nanoparticles possessing excellent microwave absorption properties

Expeditious synthesis of diverse spiro fused quinoxaline derivatives using magnetically separable core–shell CoFe₂O₄@SiO₂‐SO₃H nanocatalyst under ultrasonication