Doped Zinc Ferrite Research Articles

Enhanced Photocatalytic Performance of Zinc Ferrite Nanocomposites for Degrading Methylene Blue: Effect of Nickel Doping Concentration

In the present work, undoped and nickel doped zinc ferrite (ZnFe2−xNixO4) nano-composites were synthesized using a facile auto-combustion method using glycine as fuel. Effects of Ni dopant concentration and annealing process on structural and morphological properties were investigated by X-ray Diffraction (XRD), Raman spectroscopy, Fourier Transform InfraRed (FTIR) spectroscopy, and Scanning Electron Microscopy/Energy-dispersive X-ray spectroscopy (SEM/EDS). The formation of cubic spinel ferrites is confirmed by XRD analysis while asserting particles with a size range of 55–58 nm. Analysis of Raman spectra showed a transition of normal to inverse spinel-type with the increase in Ni content. Photocatalytic studies of as-synthesized nanoparticles using methylene blue (MB) demonstrated a strong correlation between photocatalytic efficiency and Ni doping. Ni-doped zinc-ferrites exhibited 98% photocatalytic efficiency at an optimum Ni doping concentration of 30%. As-synthesized ferrites have the potential to be used as an efficient, reusable, and magnetically removable photocatalyst system for removing organic pollutants.

Rare earth metal (Sm) doped zinc ferrite (ZnFe2O4) for improved photocatalytic elimination of toxic dye from aquatic system

Wastewater remediation is the serious topic that must be taken into concern which would be a most crucial problem that destroys the natural properties as well as it has some worse effect on living organisms. By doing better wastewater management, the scarcity of water for domestic purposes can be eventually managed. Dyes are main organic pollutant that must be removed from wastewater. Pristine, 1% Sm doped and 2% Sm doped ZnFe2O4 were prepared through simple co-precipitation method. The materials were further analyzed for its structure, optical properties, rotational properties and morphology studies. These analyses were investigated with respect to X-ray diffraction, UV–vis spectroscopy, photoluminescence and scanning electron microscopic studies. XRD pattern of Pristine, 1% Sm doped and 2% Sm doped ZnFe2O4 was matched with JCPDS Card #89–1012 with cubic phase. Bandgap energy of prepared samples were 1.7 eV, 1.65 eV and 1.47 eV. The prepared cationic dye was degraded with help of visible light irradiation. 2% Sm doped ZnFe2O4 nanoparticles easily removed 65% of dye within 1 h duration. 2% Sm doped ZnFe2O4 was tested for its reusability and efficiency was stable for more than three cycles. This shows the stability of the sample towards degrading the cationic dye. By the doping of Samarium, ZnFe2O4 nanoparticles enthusiastically removed cationic dye and it proves to be an efficient candidate in removing dyes and can help in wastewater treatment in upcoming era.

<p><strong>Genotoxic effect of manganese and nickel doped zinc ferrite (Mn<sub>0.3</sub>Ni<sub>0.3</sub>Zn<sub>0.4</sub>Fe<sub>2</sub>O<sub>4</sub>) nanoparticle in Swiss albino mouse <em>Mus musculus</em></strong></p>

Manganese and Nickel doped Zinc Ferrite (MNZF) nanoparticle Mn0.3Ni0.3Zn0.4Fe2O4 is used in fabrication of room temperature (25-30ºC) NH3 gas sensor in large scale industries. However, there are no studies available on its toxic effects. Hence, in the present study, we assessed the genotoxic effect of various doses (125, 250 and 500 mg/kg) of the MNZF nanoparticle (NP) in Swiss albino mice Mus musculus employing the chromosomal aberration test, micronucleus test and single cell gel electrophoresis assay (comet assay). The NP was orally gavaged for 15 consecutive days. Dose-dependent study was conducted at 24 h after the last dose of gavage and time-dependent response was studied for 250 mg/kg at 24, 48 and 72 h of treatment. All the parameters employed showed a statistically significant dose-dependent increase of genetic damage indicating the genotoxic effect of this NP in Swiss albino mice. Proper precautions should be undertaken on handling this NP to avoid contact with it either through respiration or ingestion.

A study of dielectric relaxation properties of ZnFe2-xBixO4 nano Ferrites synthesized by sol-gel combustion method

A series of bismuth doped zinc nano ferrite particles with the r formula ZnBixFe2-xO4 (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method; and these compositions were sintered at 600°C for 5 hrs. With the effect of bismuth doping, the structural properties of all prepared samples were characterized by X-ray diffraction (XRD). The X-ray diffraction spectra analyses confirm single phase cubic (FCC) spinal structure. The average crystallite size (D) of the samples found to be in the range 17-20 nm. The dielectric properties viz., dielectric constant (ε′), dielectric loss tangent (tan δ) and AC conductivity σAC) were measured at room temperature in the range 20Hz to 2MHz, which confirm the normal ferrite behavior. In the present research work, we are intended to extend dielectric relaxation studies of these samples with the help of Cole-Cole plots. The Cole-Cole plots of the bismuth doped zinc ferrites were drawn as a function of ε′ and ε″ (where, ε″=ε′ tan δ) and hence we have determined the spreading factor (β) for all the samples. It was observed that β decreases with the increase of the concentration of B2O3. It is noticed that the dielectric parameters ε′, tan δ and σAC have exhibited the similar trend. These samples may find suitable applications in electrolytic elements in battery technology.

Synthesis, characterization, optical and photocatalytic activity of yttrium and copper co-doped zinc ferrite under visible light

In this study, yttrium doped zinc ferrite (ZnFe2−xYxO4x = 0.01–0.1) and yttrium and copper co-doped zinc ferrite (CuyZn1−yFe2−xYxO4x = 0.1 and y = 0.5) were synthesized by solution combustion method. The synthesized nanoparticles were authenticated by various techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy–energy dispersive X-ray analysis (SEM-EDAX) and UV–visible spectroscopy. The photocatalytic activity of synthesized nanoparticles was studied by performing the degradation of methylene blue (MB) under visible light. 95% of MB was degraded in 180 min using yttrium-doped zinc ferrite. 89% of MB was degraded in 30 min using copper and yttrium co-doped zinc ferrite under visible light using 10 mg of the catalyst and 50 µl of hydrogen peroxide. Photocatalytic degradation of colorless pollutant bisphenol A also carried out using the doped zinc ferrite.

Development of Nickel Doped Zinc Ferrite Nanocomposites as Magnetically Recoverable Catalytic Material for The Synthesis of Biphenyl Methane

Magnetically active nickel doped zinc ferrite nanoparticles with chemical composition NixZn1-xFe2O4 (x- 0.0, 0.25, 0.5, 0.75 and 1.0) were successfully synthesized by sol-gel auto-combustion method using high purity metal nitrates and ethylene glycol as gelling agent. The prepared samples were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray Fluorescence (XRF) and Fourier Transform Infra-Red spectral (FTIR) analyses. TEM images and particle size distribution profile reveals the agglomeration tendency during nickel doping suggest the magnetic nature of particles. The remarkable change in the magnetic behaviour of nickel doped zinc ferrite samples provide an easy recovery and regeneration of the material and thus making an excellent candidate for benzylation reaction without any remarkable fall in the catalytic performance for repeated cycles.

Effect of Al doping in zinc ferrite nanoparticles and their structural and magnetic properties

Aluminum doped zinc ferrite (ZnFe2−xAlxO4) nanoparticles with x ranging from 0 to 0.9 was prepared via thermal treatment method using PVP as a capping agent. The Al-dopant concentration was controlled by ratio of Al/Fe precursors. Structural, morphological, and magnetic properties were investigated for the effect of non-magnetic Al in ferrite samples. Single phase with normal spinel ferrite structure was revealed by XRD measurement. Furthermore, reduction in nanocrystalline particle size as the Al content increases has been confirmed by XRD analysis. It was discovered that particle size decreases as the Al concentration increases, which attributed to structural effect of Al on grain size. Complete formation of stable nanocrystalline ferrite at 500 °C was discovered by TGA measurement. Magnetic hysteresis loop measured at RT with a maximum magnetic field of 1.8 T revealed that Ms and Mr both decreased, which ascribed to the results of spin non-collinearity and weak interaction between sublattices.

Solid state properties of zinc ferrite in presence of dopants

Different methods for the preparation of zinc ferrite in the presence and absence of different dopants have been discussed. X-ray diffraction and SEM studies have been used for the characterization of ferrites. Optical, magnetic and electrical properties of doped zinc ferrites have been discussed and it is found that all the properties changed with dopants and their concentrations.

Facile synthesis and characterization of TiO2–graphene–ZnFe2−x Tb x O4 ternary nano-hybrids

Rare earth ion (Tb3+)-doped zinc ferrite (ZnFe2O4) nanoparticles grown on reduced graphene oxide (RGO) prepared through sol–gel method have been reported. During the sol–gel process, graphene oxide was reduced to RGO, and, subsequently, anatase TiO2 and cubic spinel ZnFe2−x Tb x O4 were grown in situ on the surfaces of the RGO nano-sheets. The structure, surface morphology and chemical composition of ternary nano-composites were studied using scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, photoluminescence spectra and vibrating sample magnetometer (VSM). XRD results showed that the produced TiO2 was composed of anatase and some rutile phases and ZnFe2O4 with a cubic spinel structure. The particle sizes of ZnFe2O4 and TiO2 nanoparticles were in the ranges of ~65–80 and ~17–20 nm, respectively. The saturation magnetization (M S) determined from VSM was found to linearly increase with Tb3+ concentration.

Efficacy of heat generation in CTAB coated Mn doped ZnFe2O4 nanoparticles for magnetic hyperthermia

Manganese doped Zinc ferrite (Mn–ZnFe2O4, where Mn = 0%, 3%, 5% and 7%) nanoparticles were synthesized by a simple co-precipitation method. CTAB (cetyltrimethylammonium bromide) was used as a surfactant to inhibitgrowth and agglomeration. In this work, we have discussed on the influence of CTAB and Mn doping in tailoring the structural and magnetic properties of Mn–ZnFe2O4 nanoparticles for the effective application of magnetic hyperthermia. X-ray diffraction (XRD) pattern confirmed the formation of cubic spinel structure of Mn–ZnFe2O4 nanoparticles. Lattice parameter and x-ray densities were obtained from the Rietveld refinement of the XRD pattern. The presence of CTAB as a stabilizing layer adsorbed on the surface of the nanoparticles were confirmed by transmission electron microscope (TEM) and Raman vibrational spectrum. The saturation magnetization showsan increasing trend with Mn addition owing to cationic re-distribution and an increase super-exchange interaction between the two sub-lattices. Superparamagnetic behaviorof Mn–ZnFe2O4 nanoparticles were confirmed by temperature-dependent zero-field-cooling (ZFC) and field-cooling (FC) magnetization curves. The efficiency of induction heating measured by its specific absorption rate (SAR) and intrinsic loss power (ILP) value varies as a function of saturation magnetization. It has been hypothesized that the maximum generation of heat arises from Neel relaxation mechanism. The optimum generation of heat of Mn–ZnFe2O4 nanoparticle is determined by the higher frequency (f = 337 kHz) range and maximum concentration of Mn doping.

Effect of chromium substitution on the structural and magnetic properties of nanocrystalline zinc ferrite

Single-phase Cr doped zinc ferrites have been synthesized by hydrothermal method. The crystal structure, microstructure, crystallite size and distribution, composition and magnetic properties of the synthesized nanoparticles were determined using X-ray powder diffraction, electron microscopies and vibrating sample magnetometry. Powders are composed of ultrafine spherical nanoparticles with a highly homogeneous elemental composition. The nanoparticles have partially inversed cubic spinel structure with average crystallite size below 10 nm. Superparamagnetic behavior is observed at high temperature while ferrimagnetic ordering and surface spin canting is reported at 5 K. Substitution of Fe with Cr ions controls both structural and magnetic parameters.

Structural, morphological, magnetic and dielectric characterization of nano-phased antimony doped manganese zinc ferrites

Nano-phased doped Mn–Zn ferrites, viz., Mn0.5−x/2Zn0.5−x/2SbXFe2O4 for x=0 to 0.3 (in steps of 0.05) prepared by hydrothermal method are characterized by X-ray diffraction, Infrared and scanning electron microscopy. XRD and SEM infer the growth of nano-crystalline cubic and hematite (α-Fe2O3) phase structures. IR reveals the ferrite phase abundance and metal ion replacement with dopant. Decreasing trend of lattice constant with dopant reflects the preferential replacement of Fe3+ions by Sb5+ion. Doping is found to cause for the decrease (i.e., 46–14nm) of grain size. An overall trend of decreasing saturation magnetization is observed with doping. Low magnetization is attributed to the diamagnetic nature of dopant, abundance of hematite (α-Fe2O3) phase, non-stoichiometry and low temperature (800°C) sintering conditions. Increasing Yafet–Kittel angle reflects surface spin canting to pronounce lower Ms. Lower coercivity is observed for x≤0.1, while a large Hc results for higher concentrations. High ac resistivity (~106ohm-cm) and low dielectric loss factor (tanδ~10−2–10−3) are witnessed. Resistivity is explained on the base of a transformation in the Metal Cation-to-Oxide anion bond configuration and blockade of conductivity path. Retarded hopping (between adjacent B-sites) of carriers across the grain boundaries is addressed. Relatively higher resistivity and low dielectric loss in Sbdoped Mn–Zn ferrite systems pronounce their utility in high frequency applications.

Synthesis and Characterization of Cobalt Substituted Zinc Ferrite Nanoparticles by Microwave Combustion Method.

Pure and cobalt doped zinc ferrites were prepared by microwave combustion method using L-arginine as a fuel. The prepared samples were characterized by various instrumental techniques such as X-ray powder diffractometry, high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis, Fourier transformed infrared (FT-IR) spectroscopy, photoluminescence spectroscopy and UV-Visible diffuse reflectance spectroscopy. Vibrating sample magnetometry at room temperature was recorded to study the magnetic behavior of the samples. X-ray analysis confirmed the formation of zinc ferrites normal spinel-type structure with an average crystallite sizes in the range, 25.69 nm to 35.68 nm. The lattice parameters decreased as cobalt fraction was increased. The HR-SEM images showed nanoparticles are agglomerated. The estimated band gap energy value was found to decrease with an increase in cobalt content (1.87 to 1.62 eV). Broad visible emissions are observed in the photoluminescence spectra. A gradual increase in the coercivity and saturation magnetization (M(s)) were noted at relatively higher cobalt doping fractions.

Study of structural and magnetic properties of Nd doped zinc ferrites

ZnFe2−xNdxO4 (where x=0.012, 0.025, 0.050, 0.075, and 0.1) nanocrystalline ferrites were synthesized by the co-precipitation method followed by the heat treatment at 800°C for one hour. The morphological and structural properties of the mixed system were characterized by XRD, FTIR, TEM techniques. Infrared spectra show two strong absorption bands in the frequency range 400–600cm−1 which were respectively attributed to tetrahedral and octahedral sites of the spinel ferrite. The effect of Nd content on crystallites size, lattice parameter and X-ray density of the material has been discussed. The crystallites size of the mixed system was found in the range of 16.8–29.5nm. Magnetic properties of the material were investigated by the VSM technique. VSM results suggest that the energy of the mixed ferrite, in an external field, is proportional to its crystallite size and the number of magnetic particles in a single magnetic domain. No significant coercivities were recorded which indicates the super paramagnetic behavior of synthesized nanophase mixed ferrites.

Magnetic Properties Analysis of Rare-Earth Substituted Nickel Zinc Ferrites

The raw compounds with the chemical composition ${\rm Ni}_{0.42}{\rm Zn}_{0.58}{\rm Me}_{{{x}}}{\rm Fe}_{{2\hbox{-}{x}}}{\rm O}_{4}$ where ${\rm Me}={\rm Eu}$ , Gd, La $(x=0, 0.01, 0.02, 0.04, 0.06)$ were synthesized by means of the ceramic technique. The magnetic properties and magneto-chemical composition and structure of various doped nickel zinc ferrites were estimated by X-ray spectroscopy, EDAX analysis, and study of the behavior of susceptibility with changing temperature, complex permeability spectra, and magnetic hysteresis loop measurement.

Effects of CTAB on magnetic properties of ZnLa0.02Fe1.98O4 crystals

Abstract A facile and one-pot approach was employed to prepare nanosized La 3+ doped zinc ferrites (ZnLa 0.02 Fe 1.98 O 4 ), where hexadecyl (trimethyl) azanium bromide (CTAB) was used to modify the magnetic properties of the as-prepared samples through effects of dispersion of La 3+ in the ZnLa 0.02 Fe 1.98 O 4 crystals. The lattice constant, crystallite size, M s , M r , and H c values of ZnLa 0.02 Fe 1.98 O 4 crystals decrease with the increasing concentration of CTAB from 0.5 to 1.2 mM. However, the ZnLa 0.02 Fe 1.98 O 4 crystals prepared without CTAB show special magnetic properties compared with those samples fabricated with CTAB, such as the crystallite size is smaller and M s , M r , and H c values are higher than the sample fabricated under 1.0 mM CTAB. The formation of LaFeO 3 for the sample fabricated under 1.0 mM CTAB may duce this change.

Microwave combustion synthesis, structural, optical and magnetic properties of Zn1−xSrxFe2O4 nanoparticles

Abstract Pure and strontium doped zinc ferrite (Zn 1− x Sr x Fe 2 O 4 ) nanoparticles were prepared by the microwave combustion method using urea as the fuel. Rietveld refinements of X-ray diffraction pattern confirm the formation of single cubic spinel phase with an average crystallite size in the range of 25–42 nm. The broad visible emission band is observed in the entire photoluminescence spectrum. The estimated band gap energy is found to decrease with increasing Sr content, i.e. 2.1–1.72 eV. Magnetic measurements at room temperature revealed that at lower Sr concentration ( x ≤0.2), the system shows a superparamagnetic behavior, whereas at higher Sr concentration ( x ≥0.2), it becomes ferromagnetic. The relatively high saturation magnetization of the as-prepared Sr-doped ZnFe 2 O 4 nanoparticles suggest that this method is suitable for preparing high-quality nanocrystalline magnetic ferrites for practical applications. The mechanism for the formation of ZnFe 2 O 4 by the microwave combustion method is also discussed in the present study. Microwave combustion produced sufficient energy for the formation of ZnFe 2 O 4 , because of its homogeneous distribution within the raw materials. This results in the formation of nanoparticles and early phase formation within few minutes of time.

Modified magnetic properties of ZnLa0.02Fe1.98O4 clusters by anionic surfactant with solvothermal method

An anionic surfactant, sodium dodecyl sulfate (SDS), was used to modify fabrication of La3+ doped zinc ferrite (ZnLa0.02Fe1.98O4) clusters with a facile and efficient one-pot solvothermal method, where these clusters were aggregated by magnetic nanoparticles. The effects of SDS on magnetic properties of the samples were investigated. The saturation magnetization (Ms) of the samples increases when the concentration of SDS is increased to 15mM, and it decreases when the concentration of SDS further increased to 20mM. The maximum Ms of the sample is 101.0±0.2emu/g. The coercivity of the samples decreased significantly when SDS was added in the reaction systems. And it remains at about 5–8Oe when the concentration of SDS is between 5 and 20mM.

Studies on Fourier transform infrared spectroscopy, scanning electron microscope, and direct current conductivity of polyaniline doped zinc ferrite

AbstractIn situ polymerization of aniline was carried out in the presence of zinc ferrite to synthesize polyaniline/ZnFe2O4 composites (PANI/ZnFe2O4) by chemical oxidation method. The composites have been synthesized with various compositions (10, 20, 30, 40, and 50 wt %) of zinc ferrite in PANI. From the Fourier transform infrared spectroscopy (FTIR) studies on polyaniline/ZnFe2O4 composites, the peak at 1140 cm−1 is considered to be measure of the degree of electron delocalization. The surface morphology of these composites was studied with scanning electron micrograph (SEM). The dc conductivity has been studied in the temperature range from 40–160°C and supports the one‐dimensional variable range hopping (1DVRH) model proposed by Mott. The results obtained for these composites are of scientific and technological interest. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Structural and magnetic properties of Co xZn 1−xFe 2O 4 nanocrystals synthesized by microwave method

Microwave assisted combustion method was used to produce nanocrystalline cobalt doped zinc ferrite, Co x Zn 1− x Fe 2O 4, from stoichiometric mixture of (Co(NO 3) 2·6H 2O), (Fe(NO 3) 3·9H 2O), (Zn(NO 3) 2·6H 2O), and urea (CO(NH 2) 2) as a fuel. The structural, morphological and magnetic properties of the products were determined by X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) respectively. The average crystallite sizes obtained from XRD were between 35 and 39 nm. Magnetization measurements indicate that samples with less Co content have superparamagnetic behavior at room temperature. When the Co substitution increases the saturation magnetization due to the magnetic character of the Co cations substituting the non-magnetic Zn and coercivity also increase due to anisotropic nature of cobalt. The Co x Zn 1− x Fe 2O 4 nanocrystals exhibit typical features of an assembly of magnetic particles with a distribution of blocking temperatures and indicate the spin-glass behavior.