Structural phase transformations of as-synthesized Cu-nanoferrites by annealing process

Amer, M.A.; Meaz, T.M.; Hashhash, A.; Attalah, S.S.; Fakhry, F.

doi:10.1016/j.jallcom.2015.07.157

Cited by 44 publications

(11 citation statements)

References 37 publications

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“…In Figure a (inset), GO showed a sharp diffraction peak at 2θ = 10.60° representing (002) plane (DB card number 9012590), and the interlayer distance of ∼0.8 nm indicates the presence of functional group of GO . In XRD pattern of 5% GO–CuFe 2 O 4 hybrid catalyst, the diffraction peaks at 2θ = 18.39°, 30.18°, 35.49°, 37.02°, 43.08°, 53.40°, 56.86°, 62.51°, and 66.46° represent the crystal planes of (111), (220), (311), (222), (400), (422), (511), (440), and (531) of spinel CuFe 2 O 4 (DB-9012841). − Besides this, weak diffraction peaks at 2θ = 38.93°, 48.94°, and 68.31° for the crystal planes of (111), (202), and (113), respectively, of tenorite phase (DB-1011148) appeared due to the presence of trace amount of CuO. Similar crystal plane and angles of diffraction values were observed in our previous study for CuFe 2 O 4 catalyst .…”

Section: Resultsmentioning

confidence: 97%

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe₂O₄ Modified with Graphene Oxide under Visible Light Irradiation

Karim

Tarek

Ong

et al. 2018

Ind. Eng. Chem. Res.

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Photoelectrocatalytic reduction of CO 2 into valuable products can provide energy in a sustainable way with leveling off of the concentration of CO 2 in our environment. In this study, graphene oxide (GO) incorporated with copper ferrite (CuFe 2 O 4 ) has been employed to enhance photoelectrocatalytic CO 2 reduction under visible light. The TEM and XPS characterization indicated a strong interaction between the CuFe 2 O 4 and GO in the hybrid catalyst. The GO incorporation reduced the e − /h + recombination in the hybrid catalyst by trapping the photoexcited electrons from CuFe 2 O 4 leading to high methanol yield of 28.8 μmol L −1 cm −2 at 20.5% quantum efficiency. The incident photon current efficiency (IPCE) and Faradaic efficiency for methanol formation were observed as 8.02% and 87%, respectively. The results showed that the photoelectrocatalytic activity for CO 2 reduction can be improved by incorporating GO with CuFe 2 O 4 , and it provides a universal platform to fabricate GO−CuFe 2 O 4 based hybrid photocatalyst with promising applications in CO 2 reduction.

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Section: Resultsmentioning

confidence: 97%

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe₂O₄ Modified with Graphene Oxide under Visible Light Irradiation

Karim

Tarek

Ong

et al. 2018

Ind. Eng. Chem. Res.

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“…It is well known that CuFe 2 O 4 spinel undergoes a tetragonal lattice distortion owing to cooperative Jahn-Teller (JT) effect and stabilizes into both tetragonal (I41/amd) and cubic (Fd-3m) symmetries depending on the prevailing thermal treatment conditions during synthesis [16,17]. Furthermore, because of their excellent catalytic activity, low-dimensional CuFe 2 O 4 has often been used as a reaction catalyst in the steam reforming of methanol, water gas shift reaction, and CO oxidation [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

The role of Zn and Ru substitution on the structural, magnetic and dielectric properties of ferrite cuprospinels

Roy-Chowdhury,

Jena,

Khadse

et al. 2023

J. Phys. D: Appl. Phys.

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A comprehensive study on the structural, magnetic and dielectric behavior of ferrite cuprospinels with site specific substitution of non-magnetic Zn and weakly magnetic Ru ions has been presented. Such substitution leads to two classes of stable crystal symmetries (i) Tetragonal (I41/amd): CuFe1.95Ru0.05O4 and Cu0.95Zn0.05Fe1.95Ru0.05O4 and (ii) Cubic (Fd-3m): Cu0.60Zn0.40Fe1.95Ru0.05O4 and Cu0.05Zn0.95Fe1.95Ru0.05O4 bulk polycrystals. The former set of compounds undergo significant Jahn-Teller (JT) distortion due to high Cu content and such distortion gets lifted with the substitution of non-magnetic Zn ions. Ferrimagnetic (FiM) behavior is predominant in all these compounds except the highest Zn (95 at%) content cubic system with diluted substitution of Ru (2.5 at%) which exhibits antiferromagnetic (AFM) ordering below the Néel temperature (TN ~ 10.9 K). We employed Néel’s expression for FiM systems applicable for the two sublattice model to extract the dominant exchange interactions (JAA, JAB and JBB) between the A-site and B-site cations. For the tetragonally distorted Zn diluted system exhibits JAA/kB ~391 K with very high asymptotic Curie temperature, while the Zn-rich cubic system exhibits JAA/kB ~ 300 K. On the other hand, the tetragonally distorted spinel devoid of Zn exhibits dominant JBB/kB ~ 229 K with negligible JAA/kB and moderate JAB/kB (65 K) signifying that the JT active ions cause the onset of magnetic frustration and enhanced ordering temperatures. The ac-resistivity ρ(f,T) studies reveal that the mode of conduction follows Mott’s variable-range hopping (VRH) model with a linear logarithmic variation of ρac versus T-0.25. The temperature dependence of the VRH activation energy (24.5 meV ≤ Ea-VRH ≤ 67 meV at T = 50 K and 94 meV ≤ Ea-VRH ≤ 257 meV at T = 300 K) of charge carriers follows a linear behavior which indicates the presence of localized polaron in all the investigated systems.

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“…Utilization of spinel ferrite nanoparticles for device applications promotes materials' recycling because of their magnetic properties that enable their recovery. Copper and zinc spinel ferrites (CuFe 2 O 4 and ZnFe 2 O 4 ) are novel spinel ferrites that exhibit a crystal structure of cubic close-packed [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Fabrication of H2S gas sensors using ZnxCu1-xFe2O4 nanoparticles

et al. 2020

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Spinel ferrite nanoparticles can be easily retrieved and utilized for multiple cycles due to their magnetic properties. In this work, nanoparticles of a ZnxCu1-xFe2O4 composition were synthesized by employing a sol–gel auto-combustion technique. The morphology, composition, and crystal structure were examined using scanning electron microscopy, infrared spectroscopy, and X-ray diffraction. The produced nanoparticles are in the range of 30–70 nm and manifest spinel cubic structure. The nanoparticles were tested for their sensitivity to H2 and H2S gases, and the Cu-based spinel ferrite nanoparticles were found the most sensitive and selective to H2S gas. Their enhanced response to H2S gas was attributed to the production of metallic CuFeS2 that manifest higher electrical conductivity as compared with CuFe2O4. The fabricated sensors are functional at low temperatures, and consequently, they need low operational power. They are also simple to fabricate with appropriate cost.

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Structural phase transformations of as-synthesized Cu-nanoferrites by annealing process

Cited by 44 publications

References 37 publications

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe₂O₄ Modified with Graphene Oxide under Visible Light Irradiation

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe₂O₄ Modified with Graphene Oxide under Visible Light Irradiation

The role of Zn and Ru substitution on the structural, magnetic and dielectric properties of ferrite cuprospinels

Fabrication of H2S gas sensors using ZnxCu1-xFe2O4 nanoparticles

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Structural phase transformations of as-synthesized Cu-nanoferrites by annealing process

Cited by 44 publications

References 37 publications

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe2O4 Modified with Graphene Oxide under Visible Light Irradiation

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe2O4 Modified with Graphene Oxide under Visible Light Irradiation

The role of Zn and Ru substitution on the structural, magnetic and dielectric properties of ferrite cuprospinels

Fabrication of H2S gas sensors using ZnxCu1-xFe2O4 nanoparticles

Contact Info

Product

Resources

About

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe₂O₄ Modified with Graphene Oxide under Visible Light Irradiation

Photoelectrocatalytic Reduction of Carbon Dioxide to Methanol Using CuFe₂O₄ Modified with Graphene Oxide under Visible Light Irradiation