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Zinc ferrite (ZnFe2O4) and its derivatives, zinc-nickel ferrite (Zn0.5Ni0.5Fe2O4), and zinc cobalt ferrite (Zn0.5Co0.5Fe2O4) have garnered substantial attention as promising candidates for supercapacitor electrodes due to their exceptional combination of high electrical conductivity and chemical stability. This study presents the synthesis of ZnFe2O4, Zn0.5Ni0.5Fe2O4, and Zn0.5Co0.5Fe2O4 nanoparticles utilizing the co-precipitation technique, followed by a comprehensive characterization employing X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The electrochemical behavior of the nanoparticles was rigorously investigated using cyclic voltammetry, galvanostatic charge–discharge analysis, and dielectric spectroscopy. The obtained results confirmed the presence of a spinel crystal structure within the nanoparticles, underscoring their commendable electrochemical performance. Considering the combined outcomes, these findings strongly advocate for the potential applicability of ZnFe2O4, Zn0.5Ni0.5Fe2O4, and Zn0.5Co0.5Fe2O4 nanoparticles as promising supercapacitor electrodes. This investigation contributes to the expanding knowledge base regarding advanced electrode materials for energy storage applications and sets the stage for further in-depth exploration and optimization of these distinctive ferrite-based nanoparticulate systems. [ABSTRACT FROM AUTHOR]

A facile method to prepare activated ZnFe2O4 nanoparticles through novel metal ion doping using Bi3+ is demonstrated. The enhanced activity of the Bi3+-doped ZnFe2O4 nanoparticle was evaluated through Cr(VI) ions adsorption capability analysis from aqueous samples since industrial effluents have the metal ion as a major source of concern. ZnFe2-xBixO4 (x = 0.0, 0.05, 0.10, 0.15, 0.2) were synthesized using sol gel method, and a comparative adsorption efficiency study of Bi3+-doped and undoped ZnFe2O4 was performed. To understand the variation in adsorption efficiency and mechanism of adsorption on the Bi3+-doped ZnFe2O4, the adsorption study was conducted under varying adsorption conditions including pH, adsorbent dosage, contact time, initial ion concentration, and temperature. All the quantification studies regarding the adsorption were done using atomic adsorption spectroscopy (AAS). The studies suggested enhanced adsorption capability via Bi3+ doping as it can enhance the effective surface area and electrostatic charge density on the surface. Adsorption equilibrium information from this study was modeled using prominent adsorption kinetics and isotherm models, for extracting information regarding the performance of the adsorbent, rate of the adsorption and adsorption mechanism, which are imperative in the design and operation of adsorption systems. Scope of regeneration and reusability of the spent adsorbents in water treatment, which is also investigated in this work, addresses the ecological and economic demands for sustainability and also makes the wastewater treatment process cost effective. [ABSTRACT FROM AUTHOR]

In order to solve problems of high energy consumption and high carbon emissions in the process of separation zinc and iron from the neutral leaching residue using the fire methods, as well as poor leaching selectivity in the process of separation zinc and iron using the wet methods, and potassium iron vanadium slag and needle ore produced by the process of iron removal from the leachate need to be treated, the technique of separation iron and zinc by oxalic acid was proposed, and the response surface method was used to optimize the conditions for iron-zinc separation, and regression models for predicting iron and zinc leaching rates were established. Meanwhile, the mechanisms of iron-zinc separation and the behavior of the associated metals were discussed in the process of separation. The results show that it is necessary to make full use of the acidity of oxalic acid, the complexation of C2O42- with Fe3+, the property of C2O42- and Zn2+ to form insoluble ZnC2O4 to decompose ZnFe2O4 for achieving the separation of iron and zinc in the neutral leaching residue. The optimization process conditions for iron-zinc separation predicted by the response surface method are as follows: (C2O42-)TOT excess 1. 75 times of the theoretical quantity, leaching time of 170 minutes, temperature of 95 °C and liquid-solid ratio of 8 mL/g, the predicted and the actual values of iron and zinc leaching rates are 91. 48%,0. 63% and 91. 35% and 0. 64% respectively. In the process of iron-zinc separation, 91. 35%Fe is leached into the leachate as Fe(C2O4)33- and Fe(C2O4)22-, 99. 36%Zn,94. 24%Cu and 94. 42%Pb are enriched into the leaching residue as ZnC2O4, CuC2O4 and PbC2O4. It is proved that oxalic acid can decompose ZnFe2O4 at low temperature and separate iron and zinc in the neutral leaching residue, and the separation process does not discharge CO2, the technical defects of the existing iron and zinc separation process by fire methods and wet methods are solved. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new series of 6‐methoxy‐2‐naphthalene based pyrimidinones were synthesized via one pot‐three component synthetic reaction of aryl aldehydes, 6‐methoxy‐2‐acetonapthone and urea in the presence of nano zinc ferrite catalyst under conventional method. The synthesized compounds were characterized by their spectral techniques including FT‐IR, H1, C13 NMR, LCMS, and analysis of elements. Molecular docking analysis was also performed to identify the protein‐ligand interactions and binding energy of synthesized compounds. Biological studies of all synthesized pyrimidinone compounds have been measured against bacterial and fungal strains by calculating the zone of inhibition. [ABSTRACT FROM AUTHOR]

In this project, five different nanoparticles based on different ratios of iron, zinc, and manganese were synthesized to form Znx Mn1-X Fe2O4. Then, one of them was selected and polyethylene glycol was conjugated to its surface using tartaric acid to improve its biocompatibility. Also, to improve the target ability of the prepared polyethylene glycol conjugated Znx Mn1-X Fe2O4 as a nano-platform, folic acid was used as a targeting agent. The nano-platform was characterized using different techniques such as X-ray diffractometey, vibrating-sample magnetometer, ultraviolet–visible spectroscopy, field emission-scanning electron microscopy, Fourier-transform infrared spectroscopy and thermogravimetric analysis. In vivo and in vitro tests including hemolysis, blood aggregation and lethal dose showed that Zn0.5Mn0.5 Fe2O4 were the most suitable photosensitizers among all. Also, in vivo and in vitro biocompatibility analysis revealed that incorporation of polyethylene glycol can significantly improve the biocompatibility of the nano-platforms. The cytotoxicity results revealed that cell viability of cancerous cells was lower when the nano-platform was coated with folic acid and poly ethylene glycol under irradiation of visible light while whiteout shining the light, the cell viability was almost 100% for polyethylene coated nano-platform. These results can prove the great potential of folic acid to improve the photodynamic therapy performance of Zn0.5Mn0.5 Fe2O4. [ABSTRACT FROM AUTHOR]

Double ferrite nanocomposites with NiF 2 O 4 as the core and ZnFe 2 O 4 as the shell, were synthesised through combination of co-precipitation and hydrothermal methods. This two-step process resulted in formation of a cubic structured core of around 100 nm and a shell of zinc ferrite nanoparticles which are below 10 nm in size. The core/shell structures were characterised using various techniques such as XRD, Raman, TEM/EDS and VSM. In addition, Ni leaching out of these structures was tested in the ultra-pure water and saline solution. These analyses demonstrated that the shell of zinc ferrites effectively prevents Ni leaching from the core keeping the concentration of nickel well below the level usually found in drinking water. These core/shell nanocomposites exhibit a ferrimagnetic behaviour. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Arsenic, cadmium, chromium and nickel are categorized as carcinogen 1. Among these, arsenic is most toxic, which accumulates in the body cells and cause serious diseases like cancer, kidney failure, lungs and chest problems. In this project, In-Situ Graphene oxide/Zinc Ferrite (GO/ZnFe2O4) nanocomposites (NCs) were synthesized using modified Hummer's assisted with precipitation method. The NCs were characterized by UV/Visible spectroscopy, X-ray diffraction (XRD) analysis, Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray (EDX) and Fourier transformed infrared (FTIR) spectroscopy. XRD confirms the formation of NCs with average crystallite size 47 nm, 34 nm and 28 nm for GO/ZnFO(10:5), GO/ZnFO(5:2.5) and GO/ZnFO(1:0.5) respectively. The GO/ZnFe2O4 NCs were used for adsorption of As(III) from aqueous solution under the influence of time, concentration and temperature. Batch adsorption experiments were conducted to evaluate the adsorption capacity which was found in the range 80 to 98% at lower concentrations. The kinetic data followed pseudo second order. The As(III) removal data was tested for Langmuir and Freundlich adsorption models. However, Langmuir model was found better fitted. The results obtained show that GO/ZnFe2O4 NCs are effective and economically valuable adsorbents for removing As(III) ions. [ABSTRACT FROM AUTHOR]

Cancer is a major worldwide public health problem. Although there have already been astonishing advances in cancer diagnosis and treatment, the scientific community continues to make huge efforts to develop new methods to treat cancer. The main objective of this work is to prepare, using a green sol–gel method with coconut water powder (CWP), a new nanocomposite with a mixture of Gd3Fe5O12 and ZnFe2O4, which has never been synthesized previously. Therefore, we carried out a structural (DTA-TG and X-ray diffraction), morphological (SEM), and magnetic (VSM and hyperthermia) characterization of the prepared samples. The prepared nanocomposite denoted a saturation magnetization of 11.56 emu/g at room temperature with a ferromagnetic behavior and with a specific absorption rate (SAR) value of 0.5 ± 0.2 (W/g). Regarding cytotoxicity, for concentrations < 10 mg/mL, it does not appear to be toxic. Although the obtained results were interesting, the high particle size was identified as a problem for the use of this nanocomposite. [ABSTRACT FROM AUTHOR]

Nanomaterials are widely employed in wastewater treatment, among which nanoferrites and their composites hold significant prominence. This study adopts a green approach to synthesize zinc ferrite nanoparticles, subsequently integrating them with polyaniline (PANI) to fabricate the ZnFe2O4-PANI nanocomposite. Characterization of the prepared ZnFe2O4-PANI nanocomposite was conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. Using Scherrer's equation, the crystallite size of the synthesized zinc ferrite nanoparticles was found to be 17.67 nm. SEM micrographs of the ZnFe2O4-PANI nanocomposite revealed that in situ polymerization of ZnFe2O4 with polyaniline transforms the amorphous surface morphology of the polymer into a homogeneous nanoparticle structure. The adsorption of crystal violet (CV) dye onto the surface of the ZnFe2O4-PANI nanocomposite depends on pH, adsorbent dosage, temperature, concentration levels and duration. The Langmuir adsorption model fitted the data well, indicating adherence to a pseudo-second-order kinetic pattern. Thermodynamic values ΔG°, ΔH° and ΔS° indicated that the adsorption process occurred spontaneously. Advantages and disadvantages of the technique have also been highlighted. Mechanism of adsorption is discussed. From the obtained results, it is evident that the ZnFe2O4-PANI nanocomposite holds promise as a sorbent for the removal of dye from wastewater. [ABSTRACT FROM AUTHOR]

Polycrystalline and mesocrystalline zinc ferrite were successfully fabricated via a solvo-thermal method using different salt precursors. This study found that when iron sulfate salt was used as a precursor, polycrystalline zinc ferrite was formed. Polycrystalline zinc ferrite is a well-dispersed 400-nm sphere solid particle. Primary nano-crystals have highly preferred orientations; however, defects exist among the particles. When iron chloride salt was used as a substitute as a prime material, mesocrystalline zinc ferrite was synthesised. The products are shaped as hollow-spheres with an average size of approximately 500 nm and are composed of nano-crystal sub-units aligned in a highly oriented crystallographic structure. Zinc ferrite mesocrystalline samples have many voids, and the inter-spaces of their structure indicate the high porosity hollow-sphere architecture of zinc ferrite. The experimental results show that specific adsorption of Cl− and SO 4 2− ions on the surface plays a crucial role during the growth process of products with different morphologies and crystallographic structures. Cl− adsorption on the surface may promote the formation of mesocrystal hollow-sphere particles; whereas, SO 4 2− gives rise to polycrystalline solid spheres. The use of the as-prepared products as catalysts for the photo-Fenton degradation of Rhodamine B (RhB) with an H 2 O 2 oxidant under visible-light irradiation and the effects of reaction conditions, including pH, catalyst amount and H 2 O 2 contratentation on the removal of RhB, were investigated. The reuse of the catalysts and a possible catalytic mechanism were also proposed. These results indicate that mesocrystalline hollow-sphere zinc ferrite is a favourable catalyst for dye degradation photo-Fenton processes. [Display omitted] [ABSTRACT FROM AUTHOR]

Functional nanoferrites are attracting interest in photocatalytic applications due to their intriguing and excellent optical and magnetic properties. In that order, as suitable adsorbents for wastewater treatment, graphene-based nanoferrites can be tuned. In this article, ZnFe2O4/GO nanocomposites have been prepared to study the structural, optical, magnetic, and photocatalytic properties through investigational (experimental) results and theoretical insights. Further, the synthesized nanocomposites fall under the mesoporous range with an average crystalline size of around 15–18 nm with good colloidal stability. Spherically agglomerated morphology has been observed by FE-SEM analysis. Magnetic characterizations were done by vibrating sample magnetometer (VSM) with superparamagnetic behavior at room temperature (RT). Optical insights reveal that the samples exhibit good photocatalytic properties with a degradation rate of 85.8% with methylene blue (MB) organic pollutant. Hence, this article aims to study the properties of prepared ZnFe2O4/GO nanocomposites through a detailed theoretical discussion of density functional theory (DFT). [ABSTRACT FROM AUTHOR]

A facile solvent casting technique has been reported in the fabrication of surface hydroxylated ZnFe2O4 (h‐ZFO) nanoparticles (NPs) filled with poly(vinylidene fluoride) (PVDF) as a matrix. The h‐ZFO filler particles are synthesized from neat ZnFe2O4. The dielectric and electric performance of polymer‐based composites is much related to the interface binding between filler particles and polymer matrix. In this work, the surface alternation technique employed a new path is developed to improve the compatibility between ZFO particles and the PVDF matrix. These PVDF‐ZFO composites were studied by X‐ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The h‐ZFO‐PVDF and ZFO‐PVDF composites are carefully analyzed by dielectric and electric properties by a wide range of frequencies. However, the morphological analysis exhibits uniform dispersion of the h‐ZFO NPs in the PVDF matrix. The h‐ZFO‐PVDF composites have a dielectric constant of about 35 for 1.5 wt.% of filler contents. Moreover, the h‐ZFO‐PVDF composites have lower dielectric loss than PVDF‐ZFO composites. It is suggested that the strong interaction between h‐ZFO filler particles and the PVDF matrix is the main reason for the improvement of dielectric properties. The outcomes of these methods have great potential for making high dielectric constants and relatively suppressed loss PVDF‐ZFO composites for advanced practical applications. [ABSTRACT FROM AUTHOR]

This study presents the effect of chitosan on the properties of zinc ferrite nanoparticles suitable for potential biomedical applications. The co‐precipitation method is employed to fabricate these bio‐composites that exhibit excellent microstructural properties. The X‐ray diffractometer (XRD) analysis confirms the presence of a cubic spinel structure in the zinc ferrite‐chitosan bio‐composites, indicative of their crystalline nature. Scanning electron microscope (SEM) imaging revealed spherical particles with a size distribution below 100 nm, demonstrating the successful synthesis of homogenous nanosized particles. Fourier transform infrared spectroscopy (FTIR) spectroscopy analysis identifies the active functional groups within the bio‐composites, providing valuable insights into the molecular structure and interactions present in the synthesized materials. The presence of chitosan is confirmed, highlighting its role in modifying the chemical composition and enhancing the biocompatibility of the samples. UV–vis absorption spectra analysis reveals that the samples exhibits absorbance within the visible range. Vibrating sample magnetometer (VSM) analysis demonstrates the superparamagnetic behavior of the samples. Remarkably, these formulated samples exhibit superparamagnetism with zero coercivity and a magnetization of ≈0.0125 emu g−1 at 5 kOe when doped with chitosan. These properties are crucial for potential biomedical applications making it a promising candidate for various biomedical applications. [ABSTRACT FROM AUTHOR]

Soft magnetic composite powder of Ni 3 Fe/ZnFe 2 O 4 type has been obtained by mechanical milling of nanocrystalline Permalloy (Ni 3 Fe) particles with ZnFe 2 O 4 particles. The nanocrystalline Ni 3 Fe particles were synthesised by mechanical alloying of elemental Ni and Fe powder. During the milling time, some of the ZnFe 2 O 4 particles are embedded on the surface, and others are encapsulated in the volume of the Permalloy particles, creating a „raisin-bread" like structure. Also, at the surface of the Ni 3 Fe particles, a quasi-continuous layer of zinc ferrite is formed. The as formed composite particles have a structure of pseudo core-shell type, with a "raisin-bread" core. Upon mechanical milling, the phases are preserved according to X-ray diffraction (XRD) investigations, although the system magnetisation presents a slight decrease. The densification of the composite powder has been carried out using spark plasma sintering (SPS) technique at a sintering temperature range of 500–700 °C without holding time. The density and the electrical resistivity of the samples increase upon increasing the sintering temperature. Higher magnetisation is obtained for the sample sintered at 700 °C and accompanied by a lower coercive field. Upon sintering, a reaction at interface, between the Ni-based alloy and zinc ferrite occurs, leading to the formation of a new phase. The testing of the toroidal-shaped magnetic composite in the alternative current regime shows that the best results are obtained on the sample sintered at 700 °C. The losses decomposition was performed and showed that the dynamic losses become predominant after 1 kHz. The samples have been investigated by X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), vibrating sample magnetometer (VSM) for powder samples and by DC and AC magnetic investigation by hysteresisgraph method and electrical resistivity investigations for the sintered compacts. [Display omitted] [ABSTRACT FROM AUTHOR]

Zinc ferrite (ZF) nanomaterials were synthesised by the sol–gel auto-combustion method. Synchrotron-XRD confirms the formation of the pure F-d3m spinel structure whereas EDX reveals the composition of synthesised nano ZF. We investigated and compared the dielectric properties of un-irradiated pellet ZF-UI and irradiated pellets ZF-I1 (pulsed Nd:YAG laser dose of 1.2 W, λ = 1064 nm), ZF-I2 (pulsed Nd:YAG laser dose of 1.5 W, λ = 532 nm) and ZF-I3 (continuous AlGaAs diode laser of 4 W, λ = 808 nm) at room temperature. Dielectric constant (ε′) decreased prominently for ZF-UI while it decreased gradually for ZF-I1 and its decrement for ZF-I2 and ZF-I3 is very slow whereas dielectric constant (ε″) decreased prominently for ZF-UI and ZF-I1while reduced slowly for ZF-I2 and ZF-I3 in the low-frequency region. ε′ becomes ∼69% for ZF-I1 and ∼9% for ZF-I2 and ZF-I3 at a higher frequency of 2 MHz whereas ε″ for radiated samples becomes steady and nearly equitable at higher frequencies in comparison to that of ZF-UI in the measured frequency range of 10 kHz to 2 MHz. Dielectric loss (tan δ) of all irradiated samples has decreased and become ∼33% for ZF-I3, 43% for ZF-I2, nearly equal for ZF-I1 at 104 Hz and then decreased continuously up to 2 MHz when compared to tan δ for ZF-UI. The Jonscher power law has been fitted in measured ac conductivity (σac) with angular frequency (ω) graphs. DC conductivity (σdc), temperature-dependent parameter B(T) and frequency exponent (n) have been extracted. σdc for all irradiated samples has decreased and become nearly 51% for ZF-I1, 3% for ZF-I2 and 2% for ZF-I3 in comparison to that of ZF-UI whereas B(T) increased to 1.6 times for ZF-I3 and decreased to 0.7 times for ZF-I1 and 0.2 times for ZF-I2 while n shows slight decrement for ZF-I2 and ZF-I3. Interpretation from Cole–Cole plots for un-irradiated and irradiated pellets is in agreement with our investigations. These results suggest that the dielectric properties of ZF can be controlled and tuned by laser irradiation. [ABSTRACT FROM AUTHOR]

In order to enhance the efficiency of heavy metal ion extraction from aqueous medium, new nanocomposite magnetic sorbents were synthesized on the base of natural zeolite (Zt) and nanoparticles of ZnFe2O4 (F). The composition, structure and physical–chemical properties of new composites with 2% (Zt-2F), 8% (Zt-8F) and 16% (Zt-16F) of zinc ferrite were characterized by XRD, BET adsorption–desorption of nitrogen, SEM with elemental mapping, TEM and magnetometry. The sorption capacity of materials was assessed towards Cu2+ ions in aqueous solutions, for which kinetic and equilibrium features of sorption were established. The maximal sorption capacity (amax, mg/g) of the studied materials increased in the order: Zt (19.4) < Zt-2F (27.3) < Zt-8F (30.2) < Zt-16F (32.8) < ZnFe2O4 (161.3). The kinetics of the sorption process followed a pseudo-second order kinetic model. The sorption equilibrium at zinc ferrite was successfully described by the Langmuir model, while the Freundlich model better fitted the sorption equilibrium on zeolite and composites. The efficiency of Cu2+ ion extraction from 320 mg/dm3 aqueous solution was 63% for composite Zt-16F and 100% for a sample of ZnFe2O4. It was established that the proposed composite sorbents provide the operation of several cycles without regeneration, they can be easily recycled with 0.1 N HCl solution and are capable of magnetic separation. The advantages of new composites and the proposed method of synthesis allow recommending these materials as effective sorbents of heavy metals from wastewater.

The phase transition of austenitic stainless steel of commercial label CL20ES and zinc ferrite nanoparticles was studied in an oxidative atmosphere of dry air to develop a low-cost, effective technique for covering-layer fabrication. CL20ES powder and zinc ferrite powder were mechanically mixed. This mixture was studied in an atmosphere of dry air at different annealing temperatures from room temperature to 900 °C. The employed characterization techniques are X-ray powder diffraction, Mössbauer spectroscopy in the transmission geometry, and scanning electron microscopy with elemental mapping. The fabricated layers were also characterized by surface-specific techniques such as conversion electron Mössbauer spectroscopy and grazing incidence X-ray powder diffraction. The analyzed powder mixture shows resistance against oxidation in dry air and high temperatures. These results were employed to produce zinc ferrite covering layers on 3D-printed cylinders of CL20ES. The results show a predisposition of zinc ferrite to be recrystallized at temperatures above 350 °C without the production of corrosive substances on steel. The zinc ferrite layers were analyzed by an ultrasonic hardness tester as well, which proved the hardness enhancement. [ABSTRACT FROM AUTHOR]

Over the last few decades, the application of nanoparticles (NPs) gained immense attention towards environmental and biomedical applications. NPs are ultra-small particles having size ranges from 1 to 100 nm. NPs loaded with therapeutic or imaging compounds have proved a versatile approach towards healthcare improvements. Among various inorganic NPs, zinc ferrite (ZnFe2O4) NPs are considered as non-toxic and having an improved drug delivery characteristics. Several studies have reported broader applications of ZnFe2O4 NPs for treating carcinoma and various infectious diseases. Additionally, these NPs are beneficial for reducing organic and inorganic environmental pollutants. This review discusses about various methods to fabricate ZnFe2O4 NPs and their physicochemical properties. Further, their biomedical and environmental applications have also been explored comprehensively. [ABSTRACT FROM AUTHOR]

This article introduces a ternary nanocomposite‐based flexible thin film ammonia sensor developed on transparent polyethylene terephthalate (PET) substrate in the well‐known in situ chemical oxidative polymerization technique. The nanocomposite consists of three different materials: polyaniline (PANI), reduced graphene oxide (rGO), and zinc ferrite (ZF). Keeping the PANI amount constant, seven PANI/rGO/ZF (PRZ) samples are produced by performing stoichiometric variation between rGO and ZF. Later on, various structural, morphological, and spectroscopic analysis of all the composite materials is accomplished with field emission scanning electron microscopy (FESEM), high‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy (UV–Vis). The sensing performance of the as‐produced sensors toward ammonia (NH3) is examined in the concentration range from 250 ppb to 100 ppm. The study reveals the excellent sensing ability of the PRZ3 sensor (rGO = 30%, ZF = 20%) achieving minimum and maximum responsivity values of ~51% and ~1052%, respectively, at the lowest (250 ppb) and highest (100 ppm) concentration of ammonia. The sensor also exhibits admirable repeatability, good dynamic responsivity, rapid response (tres ~2.9–5 s), moderately faster recovery (trec ~37.9–69.7 s), superb linearity against ppm variation (R2 ~ 0.989), low detection limit (~123 ppb), and exceptional selectivity toward ammonia. The substrate temperature variation divulges that room temperature (30°C) is the ideal temperature for getting outstanding responsivity of the sensor. The study is further accompanied by humidity variation in the incoming air and bending flexibility test of the substrate. A compulsory and legitimate model regarding the sensing mechanism is presented at the end. [ABSTRACT FROM AUTHOR]

Globally, the textile industry contributes to pollution through accidental discharges or discharge of contaminated wastewater into waterways, significantly affecting water quality. These pollutants, including dye molecules, are environmental hazards for aquatic and terrestrial life. The field of visible light-mediated photocatalysis has experienced rapid growth, driven by the utilization of photocatalysts that can absorb low-energy visible light and effectively degrade dyes. In the present study, we report a simple method to controllably synthesize Fe2O3, ZnO, and ZnFe2O4 using the one-pot synthesis method. In the subsequent step, copper (Cu) was deposited on the surface of ZnFe2O4 (forming ZnFe2O4-Cu) using a facile, green, and cost-effective method. The synthesized samples were characterized using various techniques, including XRD, UV-Vis DRS, FT-IR, SEM-EDX, HR-TEM, XPS, PL, and BET analysis. These techniques were employed to investigate the composition, morphology, structure, and photophysical properties of as-prepared samples. The ZnFe2O4-Cu nanocomposite demonstrated efficient photocatalytic activity for degrading RhB dye pollutants under visible light. The photocatalyst was successfully reused for three consecutive cycles without significantly decreasing performance. Furthermore, during the study, the radical scavenging test emphasized the role of different radicals in the degradation of dye pollutants. This research has the potential to enable the efficient production of high-performance photocatalysts that can rapidly eliminate ecologically harmful dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

Nowadays a significant issue lies in developing approaches to diagnosing the surface composition and structure of mixed oxide materials, including in local areas. The possibilities of X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction in the local region to study the surface composition of a hierarchical ZnFe2O4 nanostructure are shown. This nanostructure is synthesized by the post-treatment of zinc oxide nanowires in an aqueous solution of an iron salt. The studies show that zinc, iron, and oxygen are uniformly distributed over the surface of the sample. It is found that the electron-backscatter-diffraction pattern corresponds to the ZnFe2O4 compound. Using X-ray photoelectron spectroscopy, iron on the surface of the sample is shown to exist in the Fe3+ and Fe2+ states, and oxygen is present both in the crystal lattice and in the adsorbed state. We make an assumption regarding the processes that occur in the synthesis of a hierarchical structure that cause these properties. It is shown that the sensor signal of the hierarchical structure during the detection of isopropyl-alcohol vapor with a concentration of 1000 ppm–1 exceeds the signal of zinc oxide nanowires. [ABSTRACT FROM AUTHOR]

In order to enhance the efficiency of heavy metal ion extraction from aqueous medium, new nanocomposite magnetic sorbents were synthesized on the base of natural zeolite (Zt) and nanoparticles of ZnFe2O4 (F). The composition, structure and physical–chemical properties of new composites with 2% (Zt-2F), 8% (Zt-8F) and 16% (Zt-16F) of zinc ferrite were characterized by XRD, BET adsorption–desorption of nitrogen, SEM with elemental mapping, TEM and magnetometry. The sorption capacity of materials was assessed towards Cu2+ ions in aqueous solutions, for which kinetic and equilibrium features of sorption were established. The maximal sorption capacity (amax, mg/g) of the studied materials increased in the order: Zt (19.4) < Zt-2F (27.3) < Zt-8F (30.2) < Zt-16F (32.8) < ZnFe2O4 (161.3). The kinetics of the sorption process followed a pseudo-second order kinetic model. The sorption equilibrium at zinc ferrite was successfully described by the Langmuir model, while the Freundlich model better fitted the sorption equilibrium on zeolite and composites. The efficiency of Cu2+ ion extraction from 320 mg/dm3 aqueous solution was 63% for composite Zt-16F and 100% for a sample of ZnFe2O4. It was established that the proposed composite sorbents provide the operation of several cycles without regeneration, they can be easily recycled with 0.1 N HCl solution and are capable of magnetic separation. The advantages of new composites and the proposed method of synthesis allow recommending these materials as effective sorbents of heavy metals from wastewater. [ABSTRACT FROM AUTHOR]

Semiconductor gas sensor mainly relies on the interaction between sensitive materials and gas to obtain gas information. Deep insight into the interaction mechanism is increasingly important for designing high performance gas sensors. Here, ZnFe2O4 microspheres (MSs) are utilized with tunable magnetism through the assistance of magnetic field to study the essential elements of sensitive processes. The gas sensing properties of ZnFe2O4 MS under different applied magnetic field intensities and various gaseous environments are systematically investigated. The results suggest that ordered magnetic moment induced by magnetic field promotes the probability of contact and reaction between gases and sensitive materials, thus significantly improving the sensitivity. Especially, ZnFe2O4 annealed at 500 °C sensor under the action of 54.6 mT magnetic field exhibits excellent ethanol detection performance (S = 67.8), which is "4 times higher than that without magnetic field. By carefully analyzing the experimental results, this research proposes a new physical model called "port docking" to re-explain the sensitivity mechanism. This work systematically studies the role of the magnetic moment in the sensing process, and provides a new idea for designing high-performance gas sensors. [ABSTRACT FROM AUTHOR]

The use of photocatalytic technology to degrade polyacrylamide in crude oil extraction wastewater is a promising approach, but there have been few reports so far. In this study, ZnFe2O4/Ba0.7Sr0.3TiO3 heterogeneous composite materials of a spinel/perovskite type with different proportions were synthesized. The composite materials with 31% ZnFe2O4 content exhibited a maximum polyacrylamide degradation efficiency of 46.54%, which demonstrated the unique role of the spinel/perovskite heterogeneous structure. When Ag nanoparticles were grown in situ on the surface of ZnFe2O4/Ba0.7Sr0.3TiO3, the photocatalytic degradation efficiency reached 81.28%. The main reason was that the introduction of Ag nanoparticles not only increased the active sites and enhanced light absorption capacity but also accelerated the separation of photo-generated charges. This work provides new ideas for the construction of spinel/perovskite heterogeneous composite materials and has reference significance for the application of photocatalytic degradation in the treatment of wastewater-containing polymers. [ABSTRACT FROM AUTHOR]

A series of pyrimidine heterocyclic compounds have been synthesized through a one-pot, three-component reaction of an aryl aldehyde, ketone and urea in the presence of nano zinc ferrite catalyst under conventional heating methods. The synthesized derivatives have been characterized by using spectral techniques such as FT-IR, 1H and 13C NMR and elemental analysis. Molecular docking studies have also been carried out to identify the protein-ligand interactions and binding affinity of the newly synthesized compounds. This work has multiple advantages of providing good yields, high efficiency and retrievable catalyst. [ABSTRACT FROM AUTHOR]

The demand for reliable gas sensing technologies in chemical, manufacturing, environmental, and occupational sites has increased in the last few decades following the global volatile gas sensor market, which is expected to grow further beyond 2025. Currently, several types of sensors have been employed for applications in different fields. Optical sensors are widely implemented in mining and environmental monitoring. Conventional food testing methods are utilized for the detection of any chemical or microbial agent in the food industry. Although robust and sensitive, most sensing technologies are expensive, labor-intensive, and necessitate the use of time-consuming gas sampling pretreatment steps, and these issues impede the achievement of quick, simple detection, portable, and cost-effective gas monitoring. For this reason, researchers around the world are investigating the possibility of using gas sensors as a promising technology that has the potential to alleviate industrial safety concerns. As a highly sensitive semiconducting metal oxide, gas sensors based on ZnFe2O4 have the potential to ensure environmental and occupational safety in real time. This review introduces and highlights recent developments in ZnFe2O4 gas sensors for application in different fields. The challenges limiting the wide application of the ZnFe2O4 sensor are outlined. Furthermore, this review discusses the common strategies adopted to improve the sensing properties of ZnFe2O4 for gas detection. Finally, future perspectives on further improvements of ZnFe2O4 sensing properties are discussed, and integration of ZnFe2O4 sensors into electronic noses to tackle the selectivity issue and how they can feature on the Internet of Things is outlined. [ABSTRACT FROM AUTHOR]

In this study, ZnFe2O4-Polyaniline (PANI), ZnFe2O4-Polystyrene (PST), and ZnFe2O4-Polypyrrole (Ppy) nanocomposites were synthesized by the adsorption method and characterized by field emission scanning electron microscopy and Fourier transform infrared spectrometer. Batch adsorption experiments were conducted for removing two types of hazardous dyes Red X-GRL and Direct Sky Blue 51 from an aqueous solution and the effect of pH, adsorbent dosage, contact time, and initial concentration of dyes were investigated. Meanwhile, kinetic, isotherm, and thermodynamic parameters were also determined. The electrolyte and surfactant effect was also tested for the prepared nanocomposites. To test the reusability desorption study was also conducted. [ABSTRACT FROM AUTHOR]

Dehydrogenation reactions are central for the production of functional molecules. Steam plays a pivotal role in ZnFe2O4-catalyzed 1-butene oxidative dehydrogenation (ODH). However, the essential effect of steam on this reaction is still unclear. Herein, we describe the structure-performance relationships of ZnFe2O4 in the presence/absence of steam by combined density functional theory and experimental studies. The catalytic performances of ZnFe2O4 under different reaction conditions were investigated. The ZnFe2O4(110) surface properties under reaction conditions and molecular reaction pathways were modeled. Free-energy profiles were calculated. We found that an oxygen-excess ZnFe2O4(110)-O termination, with an extra O atom bridging two Fe cations, is preferred under oxygen-rich conditions. However, both experimental and theoretical approaches indicate that this surface bicoordinated O is not stable at relatively high temperatures in the absence of steam, resulting in the reduction of surface Fe3+ cations to Fe2+ which are inactive in the 1-butene ODH reaction. It was found that steam interacts strongly with the ZnFe2O4(110)-O surface. Steam stabilizes the catalyst surface Fe3+ ions by converting bicoordinated O to more thermally stable hydroxyl groups. Surface hydroxyls are active sites for C-H bond cleavage in the 1-butene ODH reaction in the presence of steam. We propose that the role of steam elucidated here represents a general mode of steam influence in ODH reactions over oxide surfaces.