Copper Spinel Research Articles

Impact of Al3+ Substitution on Features of Structural Properties in Nanosized Spinel Copper Ferrites

Impact of Al3+ Substitution on Features of Structural Properties in Nanosized Spinel Copper Ferrites

Tailored solar collector coatings: Synthesis and characterization of CuFe2O4/PANI nanocomposites

This work successfully synthesized CuFe2O4 nanoparticles and CuFe2O4/PANI nanocomposites via a simple chemical precipitation method followed by in-situ polymerization. The main objective is to investigate the solar selective properties of these novel nanomaterials for solar collector applications. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy were used to characterize phase structure and crystallite sizes. Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and UV–vis spectroscopy were performed to examine the morphology and optical characteristics of the nanostructures. XRD confirmed the development of spinel copper ferrite nanoparticles and copper ferrite/PANI nanocomposites with average crystallite sizes of 20.64 ± 4.04 nm, consistent with FT-IR and Raman results. Optical direct band gaps, estimated using Tauc plots, ranged from 2.7 eV to 3.3 eV for copper ferrite nanoparticles and reduced to 2.5 eV–3.0 eV with polyaniline inclusion. Reflectance spectra showed that CuFe₂O₄/PANI nanocomposites exhibited strong solar absorptance (αs) of 95 % in the visible spectrum and reduced emittance (εt) of 1 % in the infrared region, with a superior selectivity of 96.28 %. These nanocomposites can emerge as a novel class of selective coating materials with outstanding selective optical properties.

Copper ferrite nanoparticles anchored laser-induced graphene as novel nanoenzyme for the electrochemical catalyzing and sensing of β-estradiol in serum

β-estradiol is one of the most active hormones in steroids, and it plays a vital role in the human reproductive and non-reproductive systems. Compared with other methods for detecting β-estradiol, electrochemical biosensors are economical, simple, sensitive, and rapid. Herein, spinel copper ferrite nanoparticles and laser-induced graphene (LIG) were employed to functionalize screen-printed carbon electrodes (SPCE) for the first time, and it demonstrated that they have a synergistic effect on the catalysis of β-estradiol. Differential pulse voltammetry (DPV) was used to detect the changes in the peak current generated by the oxidation of β-estradiol. The nanoparticles were characterized by Fourier infrared spectroscopy, transmission electron microscope, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and X-ray Diffraction (XRD), and the composition elements and morphology of the nanoparticles were explained. The linear range of β-estradiol detected by this method is 0.1 ∼ 100 μM, R2 = 0.9992, and the detection limit is 3 nM. The sensor has good selectivity, reproducibility, repeatability, stability, and anti-interference performance. In rat serum, the recovery of the sensor at 100, 10, and 1 μM β-estradiol was 105 % ∼ 110 %, with relative standard deviations of 2.3 % ∼ 4.0 % (N = 3). This study shows that the sensor can be applied to detect actual samples and has potential application value for female reproductive-related diseases.

A comprehensive review on the potential of copper spinel ferrite for gas sensing application

Copper spinel ferrite (CuFe₂O₄) is a promising material for the gas sensing due to its unique structural, electrical, and catalytic properties. This review focuses on the gas sensing capabilities of copper ferrite. Copper ferrite’s inverse spinel structure, rich in oxygen vacancies and flexible cation distribution, enables effective gas adsorption, making it highly sensitive to reducing and oxidizing gases. Various synthesis methods, determines the material’s particle size, morphology, and surface area, which are essential for optimizing gas sensing performance. Doping with the transition metals like nickel (Ni) and zinc (Zn) significantly enhances the material’s sensitivity, selectivity, response time, and operating temperature by increasing oxygen vacancies and improving charge transport. However, challenges remain, including high operating temperatures, cross-sensitivity to humidity, and long recovery times. Future research directions focus on lowering the operating temperature, improving selectivity, enhancing humidity tolerance, and developing nanostructured and surface-functionalized copper ferrite sensors. Furthermore, the integration of copper ferrite sensors into wearable and IoT devices, as well as field testing in real-world applications, presents exciting opportunities for expanding their use in environmental monitoring. This review highlights the current advancements in gas sensors and suggests potential strategies for overcoming existing limitations, paving the way for next-generation gas sensing technologies.

Analysis of DC Conductivity and I-V Characterization of Nanocrystalline Copper Ferrite Sample at and above Room Temperature

Spinel copper ferrite nanoparticles have wide spread technological applications. Polycrystalline copper ferrite nanoparticles is prepared by sonochemical method. The structural property is investigated by X-ray diffraction study, which reveals cubic spinel structure of copper ferrite NPs with average crystalline size of 20 nm. The temperature variation of DC conductivity of copper ferrite nanoparticles is studied. The conductivity is observed to increase with temperature which implies semiconducting nature of copper ferrite. The Mott study reveals that conduction process is three dimensional in present case. Again, p-n junction formation in the ferrite system is observed from the current voltage (I-V) study. This study further shows that the trap height increases with temperature. Ideality factor with values greater than 1 has been observed in present case.

Preparation of porous carbon supported Co element doping spinel copper ferrite for the catalytic oxidation of vanillyl alcohol

Spinel ferrite has been widely applied in the field of catalytic oxidation with its high selectivity, magnetic separation, and strong chemical stability. In this work, a series of porous carbon supported Co doping spinel copper ferrite (CuxCo1-xFe2O4@PC) were prepared via impregnation method for the catalytic oxidation of vanillyl alcohol (VAL) to vanillin (VN). The optimized Cu0.4Co0.6Fe2O4 @PC exhibited a nanoparticle morphology with mesoporous structure and BET surface area of 553.3 m2·g−1. Results showed that the conversion of VAL (CVAL) can reach to 96 % with 81 % of VN selectivity (SVN) in the presence of Cu0.4Co0.6Fe2O4 @PC at 80 °C for 40 min. Reusability experiment displayed that the CVAL (89 %) and SVN (79 %) can still achieve 92.3 % and 96.6 % of the initial ones after being used for 3 times. Furthermore, a possible pathway for the oxidation of VAL via·OH and·O2- active substances was also proposed. The work presents a supported doping spinel with enhanced VAL oxidation performance, which may be expected to apply in the field of selective catalysis.

Correction to: Fabrication and electrochemical performance of spinel copper manganese oxide nanocomposites for supercapacitor application

Correction to: Fabrication and electrochemical performance of spinel copper manganese oxide nanocomposites for supercapacitor application

Solvothermal-based synthesis of barium stannate nanosheets coupled with copper manganate nanoparticles for efficient photooxidation of tetracycline under visible light

Photocatalytic oxidation of antibiotic waste over semiconducting heterojunction photocatalysts is considered eco-friendly because it is simple and operates under light irradiation. In this work, we apply a solvothermal-based process for obtaining high surface area barium stannate (BaSnO3) nanosheets followed by adding 3.0–12.0 wt% of spinel copper manganate (CuMn2O4) nanoparticles to form n-n CuMn2O4/BaSnO3 heterojunction photocatalyst after calcination process. The CuMn2O4-supported BaSnO3 nanosheets exhibit mesostructure surfaces with a high surface area range of 133–150 m2g−1. Moreover, introducing CuMn2O4 to BaSnO3 shows a significant broadening in visible light absorption range due to bandgap reduction down to 2.78 eV in 9.0% CuMn2O4/BaSnO3 compared to 3.0 eV for pure BaSnO3. The produced CuMn2O4/BaSnO3 is used for photooxidation of tetracycline (TC) in water as emerging antibiotic waste under visible light. The photooxidation of TC exhibits the first-order reaction model. The specific dose of 9.0 wt% CuMn2O4/BaSnO3 at 2.4 gL−1 displays the highest-performed and recyclable photocatalyst for total oxidation of TC after 90 min. This sustainable photoactivity is attributed to the improved light harvesting and charges migration upon coupling between CuMn2O4 and BaSnO3.

Fabrication and electrochemical performance of spinel copper manganese oxide nanocomposites for supercapacitor application

Fabrication and electrochemical performance of spinel copper manganese oxide nanocomposites for supercapacitor application

Photoactive p-Type Spinel CuGa2O4 Nanocrystals.

Herein we report the synthesis and characterization of spinel copper gallate (CuGa2O4) nanocrystals (NCs) with an average size of 3.7 nm via a heat-up colloidal reaction. CuGa2O4 NCs have a band gap of ∼2.5 eV and marked p-type character, in agreement with ab initio simulations. These novel NCs are demonstrated to be photoactive, generating a clear and reproducible photocurrent under blue light irradiation when deposited as thin films. Crucially, the ability to adjust the Cu/Ga ratio within the NCs, and the effect of this on the optical and electronic properties of the NCs, was also demonstrated. These results position CuGa2O4 NCs as a novel material for optoelectronic applications, including hole transport and light harvesting.

Highly efficient Cu2O@CuxFeyO4 nanohybrid catalyst for the degradation of emerging pollutants

Cu2O@CuxFeyO4 nanohybrids (NHs) have been electrosynthesized by a simple and environmentally safe method to be used as catalysts for tetracycline degradation. NHs shown an average diameter of 14(5) nm and exhibit high crystallinity with spherical morphology. XPS results demonstrate a cuprite-enriched surface; meanwhile, the inner layer is composed by a nonstoichiometric copper spinel structure. The degradation has been monitored by UV–Visible spectroscopy, TOC analysis, and HPLC. The electrochemical characterization demonstrates the synergetic effect of Fe3+/Fe2+ and Cu2+/Cu+ coupling to enhance the activation of persulfate. This effect results in a greater degradation efficiency of NHs than other catalysts, namely, CuxOy, Fe3O4, and a mixture of both and Cu2O.It has been found that a previous adsorption stage before degradation does not improve the elimination of the pollutant and its length in time, with a TOC reduction of 72.6 % in 2 h. Conversely, conducting the oxidative process in a direct step resulted in a more rapid and efficient process, 82.3 % of reduction in 1 h. Through this method, the catalyst reutilization resulting in a decrease of 50 % in TOC degradation from the third use, while the TCY concentration degraded remains almost constant. This reduced catalytic activity with use might be a consequence of 1) the absence of the single Cu-oxide layer due to the leaching of mainly Cu ions but also Fe ions during the degradation tests, and, 2) the passivation of the outermost layer, mainly covered by CO species and OH groups, which hinders access to active catalyst sites.

Impact of different magnetic materials added to silver–magnetite nanoparticles on the structural, magnetic and antimicrobial properties

Different magnetic materials of spinel copper and cobalt nanoferrites added to silver–magnetite nanoparticles were fabricated by a facile, low cost, and rapid auto-combustion method to form a nanocomposite. X-ray diffraction patterns and atomic force microscopy were studied for the investigated samples and confirmed their nanosize range. Adding cobalt nanoferrite to silver–magnetite (CoAF) yielded a more pronounced effect in the magnetic measurements than adding copper nanoferrite (CuAF). This result was attributed to the much higher coercivity Hc and saturation magnetization Ms (5.7-fold and 2.8-fold, respectively) of CoAF than CuAF; accordingly, the CoAF nanocomposite can be applied to a permanent magnet. Next, the operating frequencies of the nanocomposites were calculated from the magnetic measurements. The CoAF and CuAF nanocomposites were applicable in the microwave super-high-frequency C-band and the microwave super-high-frequency S-band, respectively. Both nanocomposites were ineffective against the tested fungi but showed strong antimicrobial activities against the tested Gram-positive and Gram-negative bacteria. Thus, CoAF and CuAF nanocomposites are potential antibacterial nanomaterials for biomedical applications.

Electronic tuning of Ni-Fe-Co oxide/hydroxide as highly active electrocatalyst for rechargeable Zn-air batteries.

As a bifunctional oxygen electrocatalyst (oxygen reduction reaction (ORR) and oxygen evolution reaction (OER)), spinel copper cobaltite (CuCo2O4) is attracting significant research interest owing to the tailored Co, Cu electronic structure and ease of adjusting the electrochemically active area. However, its poor OER performance (>300 mV at 10 mA cm-2) limits its practical application for rechargeable zinc-air batteries. Therefore, we construct a CuCo2O4/NiFe LDH oxide/hydroxide interface to tune the properties of Ni, Fe and Co for enhancing OER activity and decreasing the charging overpotential of rechargeable zinc-air batteries. The obtained electrocatalysts show a low overpotential of 251 mV (10 mA cm-2), which is 91 mV lower than the overpotential (342 mV) of CuCo2O4. By in situ Raman, XPS and electrochemical analyses, we ascribe the enhanced OER activity to the increasing Ni/Fe oxidation state triggered by the charge transfer of Ni/Fe and Co, which prompts CuCo2O4/NiFe LDH to rapidly form an active surface layer. Benefiting from enhanced OER performance, zinc-air batteries with a CuCo2O4/NiFe LDH electrode display a high round-trip efficiency with a low voltage gap of ∼0.78 V (10 mA cm-2) due to the obvious decrease in the charging overpotential. These results suggest the importance of tuning the charge transfer on interfaces for designing high-efficiency electrocatalysts.

Pseudocapacitive Effects of Multi-Walled Carbon Nanotubes-Functionalised Spinel Copper Manganese Oxide.

Spinel copper manganese oxide nanoparticles combined with acid-treated multi-walled carbon nanotubes (CuMn2O4/MWCNTs) were used in the development of electrodes for pseudocapacitor applications. The CuMn2O4/MWCNTs preparation involved initial synthesis of Mn3O4 and CuMn2O4 precursors followed by an energy efficient reflux growth method for the CuMn2O4/MWCNTs. The CuMn2O4/MWCNTs in a three-electrode cell assembly and in 3 M LiOH aqueous electrolyte exhibited a specific capacitance of 1652.91 F g−1 at 0.5 A g−1 current load. Similar investigation in 3 M KOH aqueous electrolyte delivered a specific capacitance of 653.41 F g−1 at 0.5 A g−1 current load. Stability studies showed that after 6000 cycles, the CuMn2O4/MWCNTs electrode exhibited a higher capacitance retention (88%) in LiOH than in KOH (64%). The higher capacitance retention and cycling stability with a Coulombic efficiency of 99.6% observed in the LiOH is an indication of a better charge storage behaviour in this electrolyte than in the KOH electrolyte with a Coulombic efficiency of 97.3%. This superior performance in the LiOH electrolyte than in the KOH electrolyte is attributed to an intercalation/de-intercalation mechanism which occurs more easily in the LiOH electrolyte than in the KOH electrolyte.

Green synthesis of spinel copper ferrite (CuFe2O4) nanoparticles and their toxicity

Abstract In this study, magnetic spinel copper ferrite (CuFe2O4) nanostructures were eco-friendly synthesized using Nasturtium officinale extract. Physicochemical properties of these nanostructures were determined by transmission electron microscopy, field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), vibrating sample magnetometry, and energy dispersive X-ray mapping analysis. XRD patterns conform to the CuFe2O4 formation. SEM results demonstrated ceramic spinel CuFe2O4 nanostructures with spherical surface morphologies. The cytotoxicity effect of CuFe2O4 nanostructures against rat pheochromocytoma (PC12) cells was evaluated based on MTT assay. The magnetic nanostructures had low toxicity at a concentration of 250 µg/mL. It appears that these nanostructures can be considered as suitable candidates for drug delivery and other biomedical applications, because of their low toxicity effects.

Structural, dielectric, impedance and electric modulus analysis of Ni substituted copper spinel ferrites nanoparticles for microwave device applications

A series containing five samples of nickel substituted copper spinel ferrite (NixCu1-xFe2O4) nanoparticles with five different nickel concentrations varying as x = 0.00, 0.03, 0.06, 0.09, 0.12, fabricated with the aid of sol-gel auto-combustion technique. Through X-ray diffraction analysis, the structural properties of the compound were determined, which revealed that the prepared nanomaterials possess a spinel nature which was confirmed due to the existence of a secondary phase. The crystallite size was ascertained by applying the Scherrer formula, which was brought up in the range of 8–11 nm. The experimental parameters such as magnetic stirring speed, the molarity of reactants, synthesis temperature, the quantity of citric acid, and annealing were kept controlled. The substitution of nickel in copper spinel ferrite made a significant effect on the structural variables such as crystallite size stacking fault, lattice strain, micro-strain, dislocation density, bulk density, Impedance Analyzer (LCR meter) was used to get the dielectric properties in the frequency extended from 1 Hz to 20 MHz. From the obtained results it was depicted that the synthesized nanomaterials might be able to give response to the electromagnetic radiations, hence these can be usefully applied in microwave devices. Tangent loss and dielectric constant are varied due to Ni2+ content. Impedance loss shows the grain boundaries are dominant as a function of Ni2+ content. Inverse relation of AC frequency with the dielectric constant exposed the existence of Maxwell–Wagner type interfacial polarization. The various dielectric plots give awareness about the conducting grains and resistive grain boundaries that play a vital role in understanding the dielectric relaxation in the material. The ac conductivity is also determined due to Ni2+ content. From the observed electrical parameters, it can be propounded that the prepared nanocrystalline particles hold semiconducting nature and can be employed as a dielectric in low-frequency devices, and might be utilized as a conductor in high-frequency devices.

Sintering and property characterization of Copper doped Strontium Chromite by Sol gel method

This paper describes the synthesis of spinel copper Chromites (CuCr2O4) and doped Strontium copper chromite Nano-Crystalline using the sol gel method. The sample was calcined at various temperatures, including 750°C for the best results. Citric acid is a substance used to keep Nanoparticles from clumping together. The average particle size of nanoparticles was determined using powder x-ray diffraction, which revealed that as the sintered temperature is raised, the crystal size increases from 37 nm to 47 nm more. The sample was sintered at 750?C in furnace for 4 hours resulting in an increase in average grain size from 37nm to 47 nm measured using scanning Electron microscopy. The (124) phase of copper chromate having reference number 34-0424 JCPDS number obtained at 750°C with lattice parameter values 6.03?A and 7.8?A. The crystallite size is estimated to be between 37 and 47 nanometers. Similarly, SEM results show that the structure of pure copper chromites is tetragonal, and that after doping with other compounds, the structure will change according to the characteristics of Nano particles. In the PL spectra, four peaks are obtained: one at 347nm, one at 380nm, one at 500nm, and one at 600nm The EDX reading demonstrates that all of the required elements are present in the sample, with no additional impurity peaks. This demonstrates that this is a pure and successful synthesis. This also demonstrates that this is my unique and original work.

Vanadium oxide‐supported copper ferrite nanoparticles: A reusable and highly efficient catalyst for rhodamine B degradation via activation of peroxymonosulfate

AbstractA magnetic vanadium oxide nanoparticles supported on spinel copper ferrite (CuFe2O4–VOx) are prepared, characterized, and examined for the peroxymonosulfate (PMS) activation to degrade Rhodamine B (RhB) in water solution. Interestingly, the results show that despite the inability of mixture of copper ferrite and vanadium oxides nanoparticles to the effective RhB decomposition, the prepared catalyst exhibits an excellent catalytic ability toward RhB oxidation. The influence of vital parameters, such as temperature, PMS concentration, catalyst loading, and initial pH are discussed comprehensively. The kinetic studies demonstrate that the pseudo‐first‐order model is well fitted for RhB degradation in CuFe2O4–VOx/PMS system and the activation energy is estimated at 19.60 kJ mol−1. Furthermore, it is found out that the concentration of leached metal ions in solution is negligible and PMS activation is done mainly on the surface of the catalyst. A probable mechanism of PMS activation over RhB degradation is proposed based on the results of free radical quenching studies and X‐ray photoelectron spectroscopy (XPS) analysis. Radical quenching experiments using various scavengers suggest SO4•−as a main reactive species in the degradation.

Role of structure and cation distribution on magnetic and electrical properties in inverse spinel copper ferrite

CuFe2O4 (CFO) samples were synthesized using a solid-state route, adopting two separate cooling protocols subsequent to its final annealing at high temperatures. The first being quenching in water and the second air-cooling it slowly in a furnace. Rietveld study of the X-ray diffraction data confirmed the formation of cubic (Fd3‾m) and tetragonal (I41/amd or F41/ddm) phase for water-quenched and air-cooled samples, respectively. Scanning electron micrographs suggested that water quenching led to smaller grains in c-CFO. The structural phase was then confirmed by Fourier transform Infrared and Raman spectroscopy. Cation distribution and inversion parameter (x) obtained using Mössbauer spectroscopy technique suggests the presence of Cu2+ ions in both tetrahedral (A) and octahedral [B] site. The presence of a greater number of Cu2+ ions at A-site in c-CFO than t-CFO can be ascribed to its lower ‘x’ value, which further leads to the higher saturation magnetic moment (Ms) and low magneto-crystalline anisotropy in c-CFO. The higher redistribution of the Cu2+ ions from B-site to A-site and additionally smaller grain in c-CFO than t-CFO leads to significantly high ε′ and lower σac at lower frequencies. The nature of ε′ and σac plots are further explained using a complex impedance plot and its corresponding circuit prototype taking into account the influence of grain and grain boundaries resistance.

The role of green chemistry in producing spinel copper ferrite nanoparticles

The role of green chemistry in producing spinel copper ferrite nanoparticles