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The article presents a comprehensive investigation of the crystal structure, impedance spectra, magnetic, magnetodielectric, and magnetoresistive properties of (1- x)CoFe 2 O 4 – x PbTiO 3 composites with varying concentrations (х = 0, 0.2, 0.4, and 0.6). The study also examines the effects of applying a uniaxial pressure of 1 GPa to the synthesized powders using Bridgman anvils. Our findings reveal that the synthesis of these composites results in the formation of an additional phase, lead hexaferrite PbFe 12 O 19 , which exhibits multiferroic properties. Additionally, the coherent scattering region of the components is significantly reduced after mechanical activation. Notably, the real part of the resistivity ρ ′(ω) of nanostructured CoFe 2 O 4 ceramics increases eightfold at T = 240 °C. The composites demonstrate significant magnetoresistance at room temperature, reaching up to 250 %. The study also reveals that the signs of the magnetodielectric MD (B) and magnetoresistive coefficient MR (B) vary with the frequency of the measuring field for certain concentrations. Using the first-order reversal curve (FORC) method, it was observed that after nanostructuring CoFe 2 O 4 through mechanical activation, the interaction field H u shifts from ± 0.6 kOe to ± 0.8 kOe, while the coercive field H c increases from 1.05 kOe to 5 kOe. Moreover, the two-dimensional FORC maps of the composites show increased complexity, due to the formation of additional magnetic phases. [ABSTRACT FROM AUTHOR]

As a kind of magnetostrictive ceramics, cobalt ferrites are widely concerned because of its large magnetostriction and high resistivity, which are ideal for high-frequency applications. But, the high driving magnetic field due to the high magnetocrystalline anisotropy limits the practical applications of cobalt ferrites, thus, it is a still a challenge to find a balance between high magnetostriction properties and low driving magnetic fields. In this work, we investigated the effects of partially substitution of Ga3+ for Fe3+ on grain orientation and magnetic properties, attempting to maintain high magnetostriction while reducing the driving magnetic field. The CoFe 2-x Ga x O 4 (x=0, 0.05, 0.1, 0.15) with single-phase spinel structure were prepared by the conventional solid-state method. The saturation magnetization M S increased with the increase of Ga concentration, meanwhile the coercivity H c and magnetocrystalline anisotropy constant K 1 significantly decreased, which indicates the better soft magnetic characteristics of the Ga-doped cobalt ferrites. The oriented CoFe 2-x Ga x O 4 samples were obtained using magnetic field orientation technique during the powder forming process. The <001> preferred orientation was achieved in CoFe 2 O 4 samples. However, the <001> orientation degree decreased with the substitution of Ga, and the preferred orientation has changed into <111> at x=0.15. The Ga substitution affected the magnetocrystalline anisotropy and grain orientation, thereby affecting the magnetostrictive properties. As for the non-oriented samples, although the maximum magnetostrictive strain slightly decreased with Ga substitution, while there was a significant drop in the magnetostrictive saturation field. However, the magnetostriction of the oriented samples decreased significantly with the substitution of Ga due to the change of grain orientation from <001> to <111>. [ABSTRACT FROM AUTHOR]

This research investigates the impact of physicochemical properties on the thermochemical redox ability of CoFe 2 O 4 for water splitting application. Three samples with different properties (CFO-A, CFO-B, and CFO-C) are evaluated. The results reveal that particle size, Co/Fe ratio, and the spinel inversion degree notably affect the redox behavior and sintering of the material. The sample with the smallest particle size (CFO-A, 14 nm) exhibits the most pronounced sintering and the lowest redox performance. Meanwhile, the H 2 production results show the effect of the Co/Fe ratio and spinel inversion. The sample with Co/Fe = 0.5 (CFO–B), exhibits the highest H 2 production (595 μmol g−1), compared to the samples with Co/Fe = 0.6 (CFO-A and CFO-C). Thermodynamic calculations support these findings, suggesting that the thermochemical water splitting reaction is thermodynamically more favorable with a Co/Fe ratio = 0.5. The spinel inversion degree also influences the performance of the material, since CFO-B, the most efficient sample, shows the lowest inversion degree (67 %), compared to CFO-A and CFO-C (70 and 68 %). These results stress the importance of thoroughly controlling the physicochemical properties of the active redox material. [Display omitted] • Effect of material properties on thermochemical water splitting is evaluated. • Particle size <20 nm promotes highest sintering and lowest performance. • Co/Fe = 0.5 and lowest spinel inversion boosted the highest H 2 production (595 μmol g−1). • Thermodynamic study corroborates higher reoxidation feasibility for Co/Fe = 0.5. [ABSTRACT FROM AUTHOR]

A series of cobalt ferrite/cadmium oxide (CFO/CO) hetero-junctions were synthesized via an ultra-sonication approach. The compositions were examined based on ferroelectric, optical and photo-catalytic properties. X-ray diffraction (XRD), UV–visible (UV–Vis) spectroscopy and photo-luminescence (PL) were employed for the characterization of the prepared materials. XRD analysis confirmed a distorted cubic phase with space group fm3m and grain size was in 17.6–19.2 nm range. The ferroelectric parameters were enhanced significantly by the addition of CO (CdO) into the CFO (CoFe 2 O 4) crystal lattice. The band-gap energy was decreased significantly of hetero-junctions from 3.29 to 2.54 eV. The enhanced ferroelectric polarization with low band-gap energy boosts their ferroelectric and optical responses. A reduction in PL intensity was observed in hetero-junctions. The photo-catalytic activity (PCA) of CFO and cobalt ferrite/cadmium oxide (1–4) hetero-junctions CFO/CO (1–4) was examined by photo-degradation of Methylene Blue (MB) dye under visible light exposure. The CFO/CO4 photo-catalyst exhibited superior PCA of 92% within 90 min irradiation. Additionally, photo-catalyst dose and pH effect on the kinetics of MB dye degradation was also examined. Superior PCA of CFO/CO4 in comparison to pure CFO makes this material a promising candidate for the removal of hazardous dyes in effluents under visible light irradiation. [ABSTRACT FROM AUTHOR]

In recent times, there has been a significant focus on semiconductive magnetic nanomaterials due to their potential in photocatalytic applications, primarily because of their easy recoverability. In this work, CoY x Fe 2- x O 4 nanoparticles (with varying x values: 0, 0.05, 0.10, 0.15, and 0.20) were successfully synthesized. The incorporation of Y3+ ions induced notable transformations in the structural, optical, microstructural, magnetic, and photocatalytic properties of CoFe 2 O 4 nanoparticles. Analytical techniques such as x-ray diffraction, fourier transform infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, photoluminescence, transmission electron microscopy, vibrating sample magnetometry, and electron paramagnetic resonance spectroscopy were employed to investigate these effects. The investigation into the photocatalytic degradation of methylene blue (MB) under ultraviolet light irradiation was carried out. The influence of distinct elemental compositions, catalyst quantities, irradiation durations, and initial methylene blue concentrations on the decolorization process was assessed. [ABSTRACT FROM AUTHOR]

The development of active, stable, earth-abundant, and cheap catalysts is crucial for renewable energy conversion devices. Catalysts for electrochemical water splitting are prepared using cold uniaxial pressing and consist of a superficial ferrite coating on a nickel substrate. The activity and mechanism of the oxygen (OER) and hydrogen (HER) evolution reactions on powder compacts are investigated. It is found that powder compacts are efficient catalysts for oxygen and hydrogen evolution in a 1 M KOH solution. For Ni/NiFe 2 O 4 , the current density of 10 mAcm−2 in OER and −10 mAcm−2 in HER shows overpotentials of 272 mV and −43 mV, respectively. In turn, for Ni/CoFe 2 O 4 , those overpotentials are 279 mV and −37 mV. Furthermore, using the same material for the anode and cathode in a two-electrode cell configuration, one can achieve a 10 mAcm−2 water splitting current at only 1.55 V for over 48 h without coating degradation. It is stated that the high activity towards OER and HER results from the large electrochemically active surface area and high electrical conductivity of powder compacts. The results also indicate that the most probable rate-determining steps for OER and HER are the formation of the adsorbed oxide atom and H 2 molecule, respectively. [Display omitted] • Pressed nickel and cobalt ferrite powder compacts are prepared. • Kinetics of OER and HER on ferrite electrodes are discussed. • Mechanisms of OER and HER on ferrite electrodes are discussed. • Ferrite electrodes achieve comparable activity to noble metal electrocatalysts. [ABSTRACT FROM AUTHOR]

The 0-3 type CoFe 2 O 4 -BaTiO 3 nanocomposites have been prepared by co-precipitation sintering process in this work. The structure, dielectric, magnetic properties and magnetoelectric (ME) coupling effect of nanocomposites are studied. It finds that the 0-3 connectivity in nanocomposites results in BaTiO 3 hindering the merger and growth of CoFe 2 O 4 leading to smaller particle size (in the range 52–55 nm), creating large interface area between CoFe 2 O 4 and BaTiO 3 in composites. Creating the space charge polarization dominant thereby the dielectric constant decreased sharply with increasing frequency. Magnetization data show typical ferromagnetic behavior. Nanocomposites have strong ME coupling effect, among which C40s (CoFe 2 O 4 content is 40 wt%) sample has a maximum ME coupling coefficient of 587.3 mV/cm∙Oe at 1.8 kHz. [ABSTRACT FROM AUTHOR]

Rare earth (RE) doped cobalt ferrite (CFO) nanoparticles were synthesized by sol-gel auto combustion method, and the effect mechanism of RE3+ replacing Co2+ or Fe3+ on CFO was studied for the first time. The different roles of RE added to CFO in changing cation distribution and further affecting structure and magnetism properties due to different substitution positions were focused. The crystal structure formation and crystallite size were investigated by XRD and the results showed that the replacement of Co2+ ions by RE3+ ions was more likely to lead to larger lattice distortion and smaller grains compared with the replacement of Fe3+ ions by RE3+ ions. The SEM and TEM results showed that RE3+ doping not only reduced the grain size, but also made the grain distribution more uniform. The FTIR analysis confirmed that the synthesized material belonged to the spinel structure, and the results also showed that the space shrinkage of tetrahedron (A-sites) was more likely to be caused by the substitution of RE3+ for Co2+ ions. Room temperature magnetization measurements showed that the saturation magnetization of CFO decreased with the substitution of RE3+ ions, and the change of coercivity was related to the substitution position and type of RE3+ ions. The coercivity increased significantly with the substitution of Co2+ ions by RE3+, reaching a maximum of 2423 Oe (Co 0.8 Gd 0.2 Fe 2 O 4), and decreased with the substitution of Fe3+ ions by RE3+. Due to the difference of grain size and RE3+ doping, the magnetic domain presents single or multi domain structure. It can be concluded that the substitution of RE3+ ions for different ions will cause cation rearrangement, and then the cation rearrangement and grain size together lead to a large change in the coercivity of CFO, which puts forward a new direction for the subsequent improvement of the coercivity of materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Multicomponent electrocatalysts containing carbon supports play a crucial role in influencing the hydrogen and oxygen evolution reactions which enhance the total water splitting. Herein, we report a ternary composite with cobalt ferrite, graphitic carbon nitride, and N-doped graphene quantum dots prepared via hydrothermal technique. The purity of the samples is established by carrying out various characterization methods. The intrinsic characteristics of the obtained materials are investigated by employing electrocatalytic processes in an alkaline media toward hydrogen and oxygen evolution reactions. Cobalt ferrite/graphitic carbon nitride/N doped graphene quantum dots electrocatalyst demonstrates a very low overpotential towards hydrogen evolution reaction of 287 mV at a constant 10 mA cm−2 current density in 1.0 M KOH. Tafel slope and R ct values generated are 94 mV dec−1 and 0.86 cm2, respectively. Oxygen evolution reaction studies reveal an overpotential of 445 mV at 10 mA cm−2 with a Tafel slope of 69 mV dec−1. Finally, the cell potential needed for the cobalt ferrite/graphitic carbon nitride/N doped graphene quantum dots electrode to achieve 10 mA cm−2 in total water splitting is only 2.0 V while displaying long-term stability. [Display omitted] • A ternary composite of CoFe 2 O 4 /gCN/NGQDs is prepared via hydrothermal method. • Intrinsic features of electrocatalytic active sites are studied for overall water splitting. • CGD attains 287 and 445 mV for HER and OER at η 10, respectively. • CGD ∥ CGD electrolysis system, requires only 2.0 V @ 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Anticancer drugs can be delivered more efficiently to tumor sites with fewer side effects by utilizing magnetic nanoparticles. In this research detailed examinations of the effect of polyethylene glycol (PEG) on microstructure, size distribution, morphology, magnetic performance and coating of cobalt ferrite nanoparticles (CFO) were conducted. CFO nanoparticles were functionalized by PEG under different conditions, using a facile co-precipitation process. X-ray diffraction (XRD) patterns confirmed that all detected peaks were related to the cubic single-phase spinel structure. Fourier transform infrared spectroscopy (FTIR) revealed the chemical interactions between CFO and PEG. The results of field emission scanning electron microscopy (FE-SEM) showed a uniform spherical morphology with a mean size of 24, 32, and 40 nm at PEG molecular weights of 600, 1500 and 6000, respectively. Furthermore, vibrating sample magnetometer (VSM) revealed that saturation magnetization of nanoparticles decreased by coating with PEG. Results also confirmed that PEG with a higher molecular weight created a thicker coating on CFO. Estimation of capecitabine anticancer drug loading in CFO-PEG nanoparticles investigated by UV-VIS spectroscopy indicated that composite nanoparticles with a PEG molecular weight of 6000 had the highest loading efficiency of 13.67%. Over 40% of capecitabine was released in tumor-like acidic pH (5.5) compared to 23% in normal tissue pH (7.4). Nanoparticles proved blood biocompatible in terms of hemolysis up to a high concentration of 800 μg/ml. Eventually, magnetic resonance imaging (MRI) analyses displayed that CFO-PEG6000 nanoparticles with a relaxivity of 81.12 mM−1 S−1 can be successfully used as an MRI contrast agent. Overall, the developed multifunctional CFO-PEG nanoparticle with potential localized and efficient drug delivery and favorable imaging capability is a promising candidate as a cancer theranostic nanoplatform. [ABSTRACT FROM AUTHOR]

The effect of cobalt ferrite (CoFe 2 O 4) nanopowder synthesised through a solvothermal method on the dehydrogenation properties of sodium alanate (NaAlH 4) was studied for the first time. The onset decomposition temperature of NaAlH 4 is significantly reduced after milling with CoFe 2 O 4 , in which the 10 wt% CoFe 2 O 4 -doped NaAlH 4 sample starts to decompose at ∼100 °C. In contrast, the as-milled NaAlH 4 begins to decompose at ∼200 °C, ∼100 °C higher than the doped sample. With respect to desorption kinetic at constant temperature of 150 °C, the 10 wt% CoFe 2 O 4 -doped NaAlH 4 sample desorbed ∼2.2 wt% hydrogen within 30 min, whereas the as-milled NaAlH 4 only desorbed below 0.2 wt% hydrogen. The Kissinger plot exhibited that the apparent activation energy (E A) for hydrogen release from NaAlH 4 is significantly reduced after adding with 10 wt% CoFe 2 O 4 -doped NaAlH 4. The E A values for the first and second stage dehydrogenation of the 10 wt% CoFe 2 O 4 -doped NaAlH 4 composite are calculated as 80.3 and 88.2 kJ/mol, respectively, and these values are reduced at approximately 34.3 and 30.5 kJ/mol compared with the as-milled NaAlH 4 (114.6 and 118.7 kJ/mol, respectively). Based on the X-ray diffraction result, the enhancement of desorption properties of NaAlH 4 with the presence of CoFe 2 O 4 is presumably due to the synergistic catalytic effect played by new active species (Co 3 O 4 and Fe) that in situ formed during the desorption process. • A CoFe 2 O 4 nanopowder was successfully synthesised through a solvothermal method. • The CoFe 2 O 4 -doped NaAlH 4 composite starts to release hydrogen at ∼100 °C. • The E A for the two stages dehydrogenation in the CoFe 2 O 4 -doped NaAlH 4 reduced to 80.3 and 88.2 kJ/mol. • The formation of in situ Co 3 O 4 and Fe phase plays a catalytic role. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fixed-bed reactor with cobalt ferrite catalyst was constructed for the first time. • Electromagnetic induction heating additionally activates cobalt ferrite catalyst. • HCO 3 − ions significantly decrease the acute toxicity of treated water. • The CoFe 2 O 4 /H 2 O 2 /EMH/HCO 3 − system provides the best bacteria inactivation. • CoFe 2 O 4 is an environmentally friendly catalyst due to low leaching of metal ions. This work is a pioneering study demonstrating a promising breakthrough in water disinfection using a cobalt ferrite catalyst in a fixed bed. The performance of CoFe 2 O 4 in E. coli inactivation is due to HO• radicals generated in the Fe3+/Fe2+ and Co3+/Co2+ redox cycles. In contrast to existing reports using cobalt ferrite nanoparticles, the bulk cobalt ferrite provides long-lasting catalytic performance in a flow reactor. The positively charged surface of cobalt ferrite attracts negatively charged E. coli membranes, which enhances disinfection. The CoFe 2 O 4 catalyst was synthesized by the flow co-precipitation method, which allows obtaining kilogram quantities needed for industrial applications. The efficiency of E. coli inactivation was studied as a function of H 2 O 2 concentration. For the first time, the reactor with a CoFe 2 O 4 catalyst was additionally boosted by an electromagnetic field to decompose H 2 O 2 and inactivate bacteria. The electromagnetically heated CoFe 2 O 4 /H 2 O 2 system provides a significant 6 log bacterial inactivation. Importantly, cobalt ferrite is very stable under operating conditions. Only a negligible leaching of Fe and Co ions was observed. The presence of inorganic anions was beneficial for the bacterial inactivation. Ecotoxicological analysis revealed the absence of the toxicity of the treated water after using CoFe 2 O 4 /H 2 O 2 with electromagnetic heating in the presence of bicarbonate ions. The results show that the magnetic cobalt ferrite is a promising, durable, heterogeneous catalyst for large-scale water disinfection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nb 2 O 5 -CoFe 2 O 4 nanocomposite is a photocatalysis, working under solar radiation. • The synthesized nanocomposite is magnetic retrievable, facilitating the separation process. • Its application significantly reduced the level of toxic complex organic dye. • The composite structure was formulated with semi conductive properties of Nb 2 O 5. Electrochemical oxidations of complex toxic dyes have been widely investigated on metal–organic-framework, which are often limited by high energy demand or deactivation of organic support. Here, the potential application of a magnetically retrievable solar-driven nanocomposite of Nb 2 O 5 -CoFe 2 O 4 for removing crystal violet was explored and compared under simulated solar radiation (60.82 mW/cm2) or darkness. In the synthesized composite, Nb 2 O 5 exists as a dispersed phase on CoFe 2 O 4 , forming a core–shell structure. Both the optical and magnetic behaviour of Nb 2 O 5 -CoFe 2 O 4 were extensively investigated to optimize their photocatalytic applications in the removal of crystal violet. The nanocomposite was strongly ferromagnetic even after loading Nb 2 O 5 on cobalt ferrite. The photocatalytic performance of the composites showed a positive relationship with the Nb 2 O 5 content, where optimum degradation was observed with 50 % Nb 2 O 5 -CoFe 2 O 4. The ferromagnetic property was exploited to retrieve the catalyst from the water after the purification process. This study demonstrates the facile method for the novel Nb 2 O 5 -CoFe 2 O 4 synthesis and elucidates its high potential in sustainable remediation of complex toxic dyes using solar energy and as reusable magnetic recovery in aqueous systems. Also, 50 % Nb 2 O 5 -CoFe 2 O 4 has been implemented in water purification processes and pollutant degradation, thereby definitely amplifying the prospects for sustainable development of this research work. [ABSTRACT FROM AUTHOR]

A higher surface-to-volume ratio typically enhances capacitance in supercapacitor electrodes. However, excessive porosity can increase electrical resistance, counteracting this benefit. This study optimized the compaction level of CFO (Cobalt Ferrite Oxide) nanoparticles for enhanced supercapacitor performance. Nanoparticle-assembled CFO films with varying compaction were produced via pulsed laser deposition while maintaining consistent crystal structure and particle size. Characterization using electron microscopy and electrochemical techniques revealed a strong correlation between compaction and capacitance. All CFO nanoparticle-assembled films exhibited superior pseudocapacitive behavior compared to CFO thin films, with the most compacted nanoparticle-assembled film achieving a high areal capacitance of 6 mF cm−2. • Electrochemical properties of pulse laser deposited (PLD) films depend on chamber pressure. • PLD can produce nanoparticle-assembled films of cobalt ferrite with higher porosity. • PLD chamber pressure modifies nanoparticle compaction but preserves their size. [ABSTRACT FROM AUTHOR]

Microbial desalination cell (MDC) is an emerging technology in which water is desalinated and energy is generated by the breakdown of organic compounds and catalyzed by microorganisms using the potential gradient created in the reactor. MDC efficacy is substantially influenced by the oxygen reduction reaction (ORR) occurring at the cathode, albeit potential hindrances include sluggish reaction rates and biofouling development. The present study involved synthesizing and utilizing CoFe 2 O 4 @TiO 2 nanocomposite as a multifunctional catalyst on a cathode surface for efficient ORR and dye removal. XPS, HRTEM, and XRD techniques were used to ascertain the NPs' morphology, surface properties, dimensions, and XRD patterns. Physicochemical investigation showed that the nanoparticles had a consistent distribution, a mean diameter of 18.11 nm, and a spherical shape. Researchers tested MDCs with nanoparticles (NPs). The highest power density was 4.56 W/m3, 50 % more than the MDC with a lower loading density. The desalination efficiency was found to be 60 % at 1.5 mg/cm2 CoFe 2 O 4 @TiO 2 , however, it was 80 and 81 % at 2.5 and 2.0 mg/cm2 catalyst concentrations, respectively. The dye degradation efficiency of as high as 88 % was observed with CoFe 2 O 4 @TiO 2 nanocomposite cathode MDC. The findings show that CoFe 2 O 4 @TiO 2 nanocomposite might be an economically feasible ORR catalyst, improving MDC efficiency and cost. [Display omitted] • Sol-gel synthesis of nanocomposite and its characterization is extensively investigated. • CoFe 2 O 4 @TiO 2 nanocomposite used in MDC produced a maximum power density of 4.56 W/m3. • Composite of CoFe 2 O 4 @TiO 2 cathode in MDC resulted in 81 % desalination efficiency. • Power recovery in catalyst-mediated MDC is 2.87 times higher than in the control group. • A dye degradation efficiency of 88 % at the cathode chamber was observed with CoFe 2 O 4 @TiO 2 cathode MDC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Investigated the effect of Al3+-Gd3+ co-doping on nanoscale CoFe 2 O 4. • Studied structural, morphological, surface, magnetic, electrical, and dielectric properties. • Significant influence observed across all properties with Al3+-Gd3+ co-doping. • Potential application of co-doped nanoparticles in electronic devices highlighted. The magnetic spinel ferrites nanomaterials simultaneously doped with multivalent cations have gained a lot of interest from many researchers during the last decade. Also, the doping of trivalent rare-earth ions in spinel ferrites is promising for many technological applications. Considering these facts, in this work we investigated the trivalent Al3+-Gd3+ ions co-doped cobalt ferrite nanoparticles with nominal composition as CoFe 2-2x Al x Gd x O 4 (x = 0.00, 0.03, 0.05, 0.07, 0.10). The sol–gel auto ignition route assisted by citric acid as a chelating agent was utilized to synthesize the series of nanoparticles. The Rietveld refined X-ray diffraction (XRD) patterns were analyzed to ensure the single-phase formation of nanoparticles with spinel cubic structure. The spherical-shaped grain morphology of the nanoparticles was indicated by scanning electron microscopy (SEM) images. The elemental analysis obtained by energy dispersive X-ray analysis (EDAX) revealed stoichiometric formation of the samples along with high purity. The two prominent frequency modes analogous to the spinel ferrite structure were noted in the infrared spectra assuring the successful formation of all the samples. The soft magnetic behaviour with a lower coercivity of the prepared nanoparticles was confirmed by the vibrating sample magnetometer (VSM) technique. The DC electrical resistivity plots indicated that resistivity decreases with an increase in Al3+-Gd3+ co-doping. The dielectric studies of all the samples showed increasing behaviour with an increase in Al3+-Gd3+ co-doping. All the results suggest that the Al3+-Gd3+ co-doped cobalt ferrite nanoparticles can be useful for real-world applications, specifically in nanoelectronics devices. [ABSTRACT FROM AUTHOR]

Human respiration is a vital physiological function of the body and a key metric for assessing overall health, particularly in conditions related to sleep deprivation. However, developing a real-time system for detecting sleeping position, heartbeat, and respiration is challenging yet crucial. Such a system should be easy to fabricate, comfortable to wear, and highly sensitive. In this study, we fabricated a flexible electrospun cobalt ferrite (CoFe 2 O 4 , CF) embedded polyvinylidene fluoride (PVDF) nanocomposite (NC) using an electrospinning technique. Additionally, we investigated the influence of varying CF content (0, 1, 3, and 5 wt%) on the crystalline β -phase in PVDF. The triboelectric nanogenerator (TENG) device was fabricated using PVDF-CF (P-CF) NC as the tribo-negative layer and non-woven fabric of thermoplastic polyurethane (TPU) as the tribo-positive layer. Among the four sample combinations used in this study, P-CF-3 (3 wt% CF in PVDF)/TPU TENG exhibited a significantly higher triboelectric open circuit voltage (V oc) of 5.8 V, nearly three times higher as compared to P-CF-0/TPU TENG (1.7 V). This work demonstrates an efficient method for enhancing the output efficacy of flexible TENG devices by varying the nanofiller concentration. Moreover, the fabricated TENG device was efficiently tested for real-time healthcare monitoring (HCM) and polysomnographic (PSG) related studies. This study aspires to provide a novel and pragmatic way of identifying real-time sleeping disorders and respiratory monitoring. [Display omitted] • CoFe 2 O 4 embedded PVDF tribonegative layer was fabricated using the electrospinning method. • TENG device was fabricated using the electrospun P-CF-3 as the tribonegative layer and TPU as the tribopositive layer. • A flexible TENG based on electrospun P-CF-3 was optimized and designed for real-time applications. • The spacer-free P-CF-3/TPU-based TENG was successfully demonstrated for real-time polysomnographic applications. [ABSTRACT FROM AUTHOR]

• A series of CoMn x Fe 2-x O 4 nanoparticles with x = 0.0, 0.1, 0.3, and 0.5 were prepared using the sol–gel method. • Saturation magnetization, coercivity field, and anisotropy field increase by increasing the Mn doping level up to T = 0.3. • Cation's distributions were calculated using the Rietveld refinements of the XRD patterns. • Photocurrent density is enhanced upon the application of a magnetic field for all samples. • For CoMn 0.3 Fe 1.7 O 4 photoelectrode the current density increases by 388% under light illumination with the magnetic field. An efficient photoelectrochemical water-splitting process is of paramount importance as it provides a sustainable and clean method for generating hydrogen fuel, which is crucial for addressing the world's growing energy needs while mitigating environmental concerns. Herein, the effects of applying a magnetic field on the photoelectrochemical performance of photoanodes composed of Cobalt ferrite (CoFe 2 O 4) and Manganese (Mn)-doped CoFe 2 O 4 are investigated. The CoMn x Fe 2-x O 4 nanoparticles were synthesized using a sol–gel method, with varying values of x (0.0, 0.1, 0.3, and 0.5). X-ray diffraction analysis consistently reveals a singular cubic spinel structure for all four samples. Magnetic analyses demonstrate an enhancement in magnetic characteristics, including saturation magnetization, coercivity, and anisotropy field in the CoMn 0.3 Fe 1.7 O 4 sample compared to the other three samples. Photoelectrochemical (PEC) measurements indicate that the photocurrent increases in all four samples when a static magnetic field is applied. However, the CoMn 0.3 Fe 1.7 O 4 sample shows a more pronounced enhancement. Specifically, the dark current density increases by more than 115 % when a magnetic field of 190 ± 20 mT is applied. Additionally, it rises by 387 % under light illumination with the magnetic field. This enhancement in PEC performance is attributed to electron spin polarization adjusted through the external magnetic field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Green synthesis of CoFe 2 O 4 NPs was performed using Barleria Lupulina leaves extract as a novel green precursor. • The structural, optical, morphological, and magnetic properties of the cobalt ferrite NPs were assessed by various characterization techniques. • The biosynthesized NPs show excellent anticancer activity against the human breast cancer cell lines MCF-7. • Apoptosis, reactive oxygen species (ROS) generation, and cell cycle analyses were performed to elucidate the underlying cytotoxicity mechanism. This study reports the synthesis of Cobalt ferrite (CoFe 2 O 4) nanoparticles (NPs) by a green synthesis method using the leaf extract of Barleria Lupulina. The X-ray diffraction (XRD) analysis confirms the formation of a single-phase cubic (Fd3m) structure and from the Scherrer formula the average crystallite size (30.07 nm) calculated matches with that obtained from W-H plot(34.66 nm). A bandgap of 2.02 eV was observed from the UV–Vis-DRS analysis. Fourier transform infrared spectroscopy (FTIR) was used to confirm the characteristic functional groups present in the spinel ferrite. The investigation using scanning electron microscopy (SEM) shows aggregates of nanoparticles and EDX analysis gives the chemical composition of the green synthesized ferrite sample. The distribution of particle-sizes and colloidal-stability were estimated by DLS and zeta-potential measurements. The M−H plot confirmed the ferromagnetic nature of the prepared nanoparticles. Beyond the realm of material science, we ventured into the realm of biological activity. Our synthesized cobalt ferrite nanoparticles were assessed for their toxicity on human breast cancer cell lines (MCF-7) as well as normal L929 fibroblast cell lines by MTT assay. The results show potent anti-cancer activity of the ferrite sample (LC 50 value 77.92 µg/ml) while sparing normal cells from excessive toxicity (LC 50 value 252.34 µg/ml). The results of cell viability, changes in cell morphology, and cell cycle analysis revealed that cobalt ferrite nanoparticles triggered apoptosis, and hindered cell adhesion and migration of MCF-7 cells, potentially through elevated reactive oxygen species generation. This dual action, where the nanoparticles combat cancer effectively while minimizing harm to healthy cells, holds significant promise in the field of oncology. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanoparticles Fe 3-x Co x O 4 obtained by scalable wet milling method with surfactant. • XRD, TEM data and using the Sharrock's law confirm the formation of nanoparticles. • Cobalt substitution increase the coercivity of the sample. • The maximum values of SLP and ILP of 164 W/g and 1.57 nH·m2/kg were reached. In this work, the methods of X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy (MS), magnetic properties measurements and specific loss measurements (hyperthermia) were used for the investigation of the structure and properties of Fe 3-x Co x O 4 nanoparticles. The Fe 3-x Co x O 4 nanoparticles were synthesized by using high-energy ball milling of Fe and Co mixed with water and surfactant additives. Co substitution increased the coercivity of the samples and changed the kinetics of oxidation process. The presence of cobalt ferrite was verified by MS. TEM images of synthesized samples demonstrated 5–50 nm particle size. Specific loss related heating effect depended mostly on the ratio between the samples coercivity and the amplitude of the high-frequency field. Specific loss power (SLP) and intrinsic loss power (ILP) values reached 164 W/g and 1.57 nH·m2/kg, respectively. [ABSTRACT FROM AUTHOR]

• Single phase cubic-spinel structure is formed by a facile auto-combustion method. • CCFO shows the tailored magnetostriction by variant ratio of Cu/Co, with a large saturation magnetostriction λ S ∼ 240 ppm. • An enhanced low-field magnetostriction (λ a ∼ 150 ppm@2 kOe) and a low magnetocrystalline anisotropy (K 1 ∼ 3.7 × 106 erg/cm3) are obtained. • A high piezomagnetic coefficient (d 33 ∼ 1.44 nm/A at 1.5 kOe) is achieved. The Cu-doped cobalt ferrites Cu x Co 1-x Fe 2 O 4 (CCFO) were synthesized by a glycine-nitrate sol-gel auto-combustion method and investigated for structural, magnetic and magnetostrictive properties. X-ray diffraction and scanning electron microscopy analysis revealed the formation of single cubic-spinel phase for all the as-prepared powders, followed by the sintered samples with grain sizes around 2.5 µm. The variation in stoichiometric composition can be used to tailor magnetic and magnetostrictive properties. Saturation magnetization M S decreases from 84.8 to 60.4 emu/g with increasing Cu content from x = 0.0 to x = 0.50, accompanied with a reduction in coercivity H C from 1.21 to 0.41 kOe. The introduction Cu into CFO is conductive to the decline in magnetocrystalline anisotropy, giving rise to an improvement in magnetostriction at low applied fields. An optimized composition in the Cu x Co 1-x Fe 2 O 4 ferrites is found to be around x = 0.30, achieving good magnetoelastic properties, i.e., a large saturation magnetostriction (– λ S ∼ 240 ppm), a high strain sensitivity (– dλ / dH ∼ 1.44 nm/A), as well as a low magnetocrystalline anisotropy coefficient (K 1 ∼ 3.7 × 106 erg/cm3). The excellent magnetoelastic properties and the combination in a facile synthesis process for sintered polycrystalline ferrites, suggest promising prospects in magnetostriction applications. [ABSTRACT FROM AUTHOR]

Owing to the excellent conversion properties between magnetic and electric properties, magnetoelectric composites have been widely used in devices. With the growing concerns about the environment, developing environmentally friendly lead-free magnetoelectric composites with high performance are very important. Here, (1- x)0.82Ba(Ti 0.89 Sn 0.11)O 3 -0.18(Ba 0.7 Ca 0.3)TiO 3 - x CoFe 2 O 4 [(1- x)BTS-BCT- x CFO] magnetoelectric composites are synthesized by solid-state method, and the effect of CFO on the microstructure and magnetoelectric properties is systematically studied. The perovskite type piezoelectric phase and spinel structured piezomagnetic phase in diffraction patterns are independent of each other. Due to the inhibiting effect of CFO on grain size for BTS-BCT, the grain size of magnetoelectric composites is dominated by CFO. The electric properties deteriorate, and magnetic properties increase with increasing CFO. Meanwhile, the optimal ME coefficients (α E31 ∼8.12 mV/cm∙Oe and α E33 ∼7.84 mV/cm∙Oe) are obtained in the (1- x)BTS-BCT- x CFO with x = 0.20, which are superior or comparable to that of some lead-based and lead-free magnetoelectric composites. Therefore, (1- x)BTS-BCT- x CFO material systems have a promising prospect in application. [ABSTRACT FROM AUTHOR]

This study employed the Pechini-type sol-gel method to synthesize single-phase cobalt ferrite nanoparticles with almost spherical morphology and an average size of ∼50 nm. The Pechini sol-gel is based on the polysterification reaction between citric acid and ethylene glycol and the formation of colloidal nanoparticles due to the polymerization of an iron-cobalt complex. Foam samples were prepared from the obtained nanoparticles by using urea as the progenic agent and subsequent conventional or microwave sintering. The average grain size values for the microwave and conventionally sintered foam samples were 90 and 280 nm, respectively. Microwave sintering has successfully hindered grain growth regarding the initial ∼50 nm size of the cobalt ferrite nanoparticles. The microwave sintered foam sample showed an approximately two-fold increase in the surface area value compared to its conventionally sintered counterpart. The pore volume for the conventionally and microwave sintered samples was measured at 0.007 and 0.026 cc/g, respectively. Also, the pore diameter values were measured to be less than 2.5 nm in both samples. The pore size distribution within the microwave sintered sample was unimodal, while the conventionally sintered sample showed a bimodal one. The gas-sensing properties of the samples were examined in pure ethanol, acetone, and liquefied petroleum gas (LPG) atmospheres at different temperatures. The results indicated that for all the samples and in all the three atmospheres, the best working temperature is 300 °C. The microwave sintered foam sample showed the highest sensitivity and the shortest response time. This sample was more selective towards ethanol than the other two gases. [ABSTRACT FROM AUTHOR]

Nickel ferrite (NFO) and cobalt ferrite (CFO) have been explored as promising electrocatalysts for overall water splitting in virtue of unique characteristics. However, the poor intrinsic conductivity and the limited active sites of NFO and CFO give rise to sluggish charge transfer dynamics. It is the general approach that the target products implemented as shell are tightly wrapped on the sacrificial core of silicon dioxide (SiO 2) to design the hollow/porous electrode materials, while employing SiO 2 as sacrificial shell could be a novel method to improve the specific surface area (SSA) of NFO and CFO. Herein, the porous nickel ferrite (P–NFO (V O)) and cobalt ferrite (P-CFO (V O)) microspheres with rich oxygen vacancies and enhanced SSA are reported through the novel self-activation treatment along with reduction process. The simultaneous formation of rich pore channels and oxygen vacancies could expose numerous active sites, optimize electronic configuration, and boost charge transfer. As expected, the elaborately designed P–NFO (V O) and P-CFO (V O) microspheres achieve excellent achievement for HER with low overpotentials (102.9 and 100.7 mV) and relatively small Tafel slopes (45.2 and 60.1 mV/dec), respectively. Beyond that, P–NFO (V O) and P-CFO (V O) microspheres deliver favorable overpotentials of 336.3 and 384.2 mV at 10 mA/cm2 for OER, respectively, which is highly considerable to transition metal oxide-based electrocatalysts. Overall, the versatile strategy could be employed to construct other transition metal oxides with superior electrochemical properties. • Oxygen vacancies-rich nickel ferrite and cobalt ferrite microspheres with large specific surface area are prepared. • The inverted design of SiO 2 as sacrificial shell to prepare P–NFO (V O) and P-CFO (V O) microspheresis proposed. • The induced rich oxygen vacancies could offer superior conductivity and rich active sites. • The introduction of phosphate ions is favorable for weakening the activation energy of their redox reactions. • Notably, upon employing this route, a wide range of transition metal oxides could be attained. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of the Sodium borohydride (NaBH 4) hydrolysis process particularly in alkaline conditions requires the design of high-performance low-cost catalysts. Herein, it was aimed to tailor cobalt ferrite anchored nitrogen-and sulfur-doped graphene architecture (CoFe 2 O 4 @N,S-G) via a facile production pathway, to explore its potential application as a catalyst in alkaline NaBH 4 hydrolysis reaction for hydrogen production, and to develop an optimal artificial neural network (ANN) architecture to predict hydrogen production rate. In this regard, the influence of several variables such as reaction temperature, NaBH 4 concentration, and catalyst loading was explored to determine the optimal operational conditions for effective hydrogen generation. Furthermore, the performance metrics of ANN topologies were investigated to establish the best ANN model for predicting hydrogen generation rate under different operational conditions. The experimental results offered the outstanding catalytic activity of CoFe 2 O 4 @N,S-G towards NaBH 4 hydrolysis with the volumetric hydrogen production rate of 8.5 L. min − 1 . g cat − 1 at 25 ℃ , and catalyst loading of 0.02 g, and 1.0 M NaBH 4 concentration. The CoFe 2 O 4 @N,S-G nanocatalyst was found to retain 94.9% of its initial catalytic activity after 5 consecutive uses, according to the reusability tests. The optimum performance metrics that were determined by the mean squared error (MSE) of 0.00052 and the coefficient of determination (R2) of 0.9989 were achieved for the ANN model with the configuration of 3–10–5–1 trained by Levenberg-Marquardt backpropagation algorithm. The activation function of tansig and purelin functions at hidden and output layers, respectively. The findings revealed that the experimental data were in harmony with the ANN-predicted one, thereby inferring the optimized ANN model could be employed in the forecasting of hydrogen production rate at various operational conditions. • H 2 production via hydrolysis of NaBH 4 catalyzed by CoFe 2 O 4 @N,S-G was explored. • The ANN approach was utilized to forecast H 2 production rate. • CoFe 2 O 4 @N,S-G facilitated the catalytic activity synergistic effects. • A high retention rate of 94.9% for the 5 consecutive utilizations was achieved. • The 3–5-10–1 configuration ANN model trained by trainlm was determined as the best one. [ABSTRACT FROM AUTHOR]

• Cobalt ferrite nanoparticles dispersed in silica matrix to minimize agglomeration. • Silica content can be varied to tune the optical properties. • Polarizability and nonlinearity responses increased with silica. CoFe 2 O 4 and CoFe 2 O 4 /SiO 2 were synthesized by sol-gel method. The studies carried out using XRD, FT-IR, SEM, TEM, VSM, UV–Vis DRS, and Z-scan techniques. The CoFe 2 O 4 has the inverse cubic spinal structure. TEM and SEM confirmed the less crystallite size of CoFe 2 O 4 /SiO 2 nanocomposite than CoFe 2 O 4. The results show that two samples have a pure single phase cobalt ferrite with face-centred cubic spinel phase. SiO 2 matrix in CoFe 2 O 4 nanocomposite results in reduction particle size and magnetic properties as well as enhancement band gap. The band-gap energy of CoFe 2 O 4 and CoFe 2 O 4 /SiO 2 calculated 1.76 and 1.92 eV, respectively. Our findings in nonlinear optical aspects suggest that the distinctive characteristics of CoFe 2 O 4 /SiO 2 present opportunities for advancements in telecommunications and other related fields. [Display omitted] [ABSTRACT FROM AUTHOR]

Owing to their low resistivity, metal-based magnetostrictive materials are prone to eddy current loss under high-frequency magnetic field excitation, leading to a significant decline in output characteristics. Cobalt ferrite, a new non-metal-based magnetostrictive material, possesses both high magnetostriction strain and high resistivity, making it highly promising for high-frequency driving applications. However, reports on cobalt ferrite as the core driving material for ultrasonic transducers remain limited, and research on its high-frequency vibration characteristics is insufficient. In this study, magnetostrictive samples of cobalt ferrite were prepared using a solid-state reaction method, and their morphologies and magnetic properties were characterized. Under a bias magnetic field, the dynamic magnetic properties of cobalt ferrite and temperature variations with the driving magnetic field amplitude and prestress were analyzed. The results indicated that the density of the sample prepared by solid-state reaction can reach 88 % and the saturation magnetostriction coefficient λ s can reach 186 × 10−6, with an optimal bias range of 400–600 Oe for the cobalt ferrite. When the driving magnetic field amplitude is 100 Oe in the optimal bias range, the output amplitude of the cobalt ferrite is 2160 nm, meeting the output requirement of high-frequency magnetostrictive ultrasonic transducers. • Cobalt ferrite magnetostrictive material for high frequency ultrasonic transducers was prepared based on solid state reaction. • Testing the magnetostrictive properties of cobalt ferrite using the static and dynamic magnetic properties test platforms. • The static magnetostrictivity of cobalt ferrite decreases with the decrease of density and the increase of prestress. • The dynamic magnetostrictive properties under a bias magnetic field with driving magnetic field and pre-stress was discussed. [ABSTRACT FROM AUTHOR]

• Synthesized CoZr x Fe (2-x) O 4 nanoparticles with variable doping rates. • Achieved single phase spinel with 39–59 nm particle size. • Confirmed ferrimagnetic behavior with reduced properties. • Doping boosts photocatalytic degradation of orange G dye. • Produced materials for environmental applications. In this study, CoH f x F e (2 − x) O 4 nanoparticles (x = 0.0, 0.04, 0.08, and 0.12) were synthesized using the co-precipitation method. X-ray diffraction (XRD) analysis confirmed a pure spinel phase for the x = 0.04 sample, validated by Rietveld refinement, with crystallite sizes between 39 and 59 nm. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the formation of the spinel structure and the proper valence states of the elements. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) verified the morphology and homogeneity of the samples. Magnetic property analysis revealed reduced saturation magnetization with increased Hf content. Impedance spectroscopy showed enhanced electrical resistivity with Hf incorporation. Photocatalytic tests demonstrated that doping improves the degradation efficiency of Orange G dye under UV-Vis irradiation, achieving yields between 9 % and 35 % after 60 min. [ABSTRACT FROM AUTHOR]

In this study, a surfactant assisted wet-chemical method was used to synthesize manganese and neodymium co-doped cobalt ferrite [Co 1-x Fe 2-y O 4 (x = Mn, y = Nd)]. The co-doping strategy was adopted to enhance the magnetic properties, tune the band gap, and hamper charge–recombination in the spinel ferrite during the photocatalytic application. Different dopant concentrations, namely Mn = Nd = 1.1 %, 2.2 %, 3.3 %, and, 4.4 %, were used to synthesize MNCF-1, MNCF-2, MNCF-3, and MNCF-4 samples, respectively. The pristine (CF) and co-doped samples (MNCF) were characterized via TGA, PXRD, Raman, FTIR, and UV/Vis techniques to examine the impact of co-doping on the various physicochemical and thermal properties. The optical study proposed the MNCF-4 sample with a band gap value of 2.88 eV as most suitable for visible-light harvesting. A dielectric study showed that co-doped ferrite with a higher dopant concentration (MNCF-4) exhibits boosted AC conductivity and substantially decreased leakage current as compared to the bare and co-doped samples. As the concentrations of the co-dopants increase, the coercivity field (H c) decreases while the remanent magnetization (M r) and saturation magnetization (Ms) increase. The MNCF-4 material exhibited the highest magnetic properties, ensuring its full and quick magnetic recovery at the completion of the photocatalytic process. In the context of photocatalytic applications, it was observed that the MNCF-4 catalyst exhibited a mineralization rate constant value of 0.016 min−1 for 92.5 % crystal violet (CV) dye. To mitigate the impact of dye sensitization, the photocatalytic efficiency of MNCF-4 material was assessed by using phenol as a representative colourless organic pollutant. The enhanced magnetic properties of the MNCF-4 catalyst enable its complete magnetic recovery and 90.2 % retention of the photocatalytic activities after five reusability tests. [Display omitted] • Co-doped and undoped ferrite nanostructures have been synthesized. • The structural, optical, magnetic, and electrical properties were examined. • Co-doping enhanced the magnetic properties and reduced the bang gap. • Doped ferrites showed excellent photocatalytic aptitude. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of a novel activated nanobentonite@cobalt ferrite@carboxymethylcellulose. • The particle size range was detected as 22.5–26.2 nm. • Optimized conditions for Cr(VI) removal at pH 2.0, 25–30 min, 25 mg dosage and 25 °C. • Linear and nonlinear Freundlich expressions for Cr(VI) removal were extremely relevant. • Excellent Cr(VI) recovery from diverse water matrices providing 87.9% to 95.8%. Contamination of industrial and dietary water with Cr(VI) ions is known as a global concern. Industrial wastes containing elevated Cr(VI) concentration are hazardous and harmful to people and animals, if inappropriately treated. Consequently, in the current research, a novel nanocomposite of activated nanobentonite@cobalt ferrite@carboxymethylcellulose (ANB@CoFe 2 O 4 @CMC) is generated and characterized. Several characterization techniques were employed to confirm the structure of as-prepared ANB@CoFe 2 O 4 @CMC. The mean particle size range of this nanocomposite was found to be 22.5–26.2 nm. Through batch adsorption assessments, ANB@CoFe 2 O 4 @CMC was employed and optimized to remove Cr(VI) ions from aquatic medium providing optimum conditions of pH 2.0, 25–30 min shaking time, 25 mg nanocomposite dosage at 25 °C reaction temperature. Freundlich model was extremely relevant via linear and nonlinear expression. Thermodynamic investigations were investigated to conclude that both exothermal and spontaneous tendencies in governing Cr(VI) adsorptive uptake. The ANB@CoFe 2 O 4 @CMC was remarkably stable after five subsequent runs of regenerating and recycling. This investigation displayed the potential of ANB@CoFe 2 O 4 @CMC as a powerful nanocomposite material for Cr(VI) recovery from diverse waters via a microcolum technique, exhibiting uptake values up to 87.9–95.8 %. As a result, the evaluated ANB@CoFe 2 O 4 @CMC could be successfully illustrated a superior material for effective multi-uptake Cr(VI) ions from water. [ABSTRACT FROM AUTHOR]

Nanoparticle-containing sizing agents are essential for the overall performance of high-quality carbon fiber (CF) composites. However, the uneven dispersion of nanoparticles often leads to agglomeration on the surface of CF after sizing, consequently diminishing the material properties. In this study, the properties of cellulose nanofibers (CNFs) that can respond to magnetic and electric fields were utilized to achieve three-dimensional to one-dimensional orientations in CFs containing sizing agents. Cobalt ferrite (CoFe 2 O 4) was utilized to enhance the response of CNFs to a magnetic field, and subsequently, it was combined with an electric field to attain a higher degree of orientation. The occurrence of nanoparticle agglomeration is diminished on CF surface, while establishing a structured network. The flexural strength and thermal conductivity of CF composites treated with CoFe 2 O 4 self-assembled CNF sizing agent exhibit an increase of 54.23 % and 57.5 %, respectively, compared to those of desized CF composites, when subjected to magnetic and electric fields. Consequently, the approach can depolymerize the nano-fillers within the sizing agent and orient it into the carbon fiber under the influence of magnetic and electric fields, effectively improving the mechanical properties and thermal conductivity of the composite material. [ABSTRACT FROM AUTHOR]

In recent research, semiconductive magnetic nanomaterials have gained significant attention for their potential in photocatalytic applications, primarily due to their ease of recoverability. This study focuses on the successful synthesis of CoCe x Fe 2- x O 4 nanoparticles, where the variable x (ranging from 0 to 0.20) introduces Ce3+ ions. The inclusion of Ce3+ ions induces noteworthy changes in the structural, optical, microstructural, magnetic, and photocatalytic properties of CoFe 2 O 4 nanoparticles. Various analytical techniques, including x-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, photoluminescence, transmission electron microscopy, vibrating sample magnetometry, and electron paramagnetic resonance spectroscopy, were employed to investigate these effects comprehensively. The research delves into the photocatalytic degradation of rhodamine B under visible light irradiation, exploring the impact of different elemental compositions, catalyst quantities, irradiation durations, and initial rhodamine B concentrations on the decolorization process. • Ce3+ substituted CoFe 2 O 4 nanoparticles can be used in red-emission optoelectronic devices. • Non-magnetic Ce reduces the particle size of CoFe 2 O 4. • Cation distribution and elastic parameters were calculated. • Maximum decolorization efficiency of MB dye solution is 98% for CoCe 0.20 Fe 1.80 O 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterogenous ferrospinel nanoparticles were prepared towards PMS activation to degrade BTA. • Statistical-based RSM-CCD approach was used for optimization of BTA degradation process. • CoF showed a higher catalytic activity to decompose PMS compared to CuF. • An excellent reusability was observed for the both catalysts after eight consecutive reaction runs. • HO• and SO 4 •– species were responsible for the BTA degradation in both systems. The sulfate radical-based advanced oxidation process has been widely investigated via peroxymonosulfate (PMS) activation in recent years, in which the development of catalysts with high efficiency and stability is crucial. The current work prepared a series of magnetic nanoparticles, including CuFe 2 O 4 (CuF) and CoFe 2 O 4 (CoF), for benzotriazole (BTA) degradation via PMS activation. Various techniques (XRD, VSM, BET, FESEM, and TEM) employed to examine the physicochemical, textural, magnetic, and structural characteristics of the as-prepared catalysts. Moreover, a response surface methodology (RSM) based on central composite design (CCD) used to identify the optimum levels of operational variables and explore the interactions between them. The results showed that 99.7 and 100% of BTA can be removed under optimal conditions when CuF and CoF catalysts were applied in the system in the presence of PMS, respectively. Both catalysts exhibited high degradation efficiencies, even after eight consecutive cycles, highlighting their high stability and reusability in decontamination applications. According to the trapping tests, HO• and SO 4 •– species were responsible for the BTA degradation in both systems. These results suggested that CuF and CoF could be applied as effective recoverable catalysts for activating PMS and degrading persistent pollutants in wastewater treatment. [ABSTRACT FROM AUTHOR]

In this study, molybdenum doped iron cobaltite and cobalt ferrite catalysts were prepared by coprecipitation, and their structural, morphological, and optical, properties were evaluated by XRD, BET, SEM, FTIR, Raman, XPS and UV–VIS techniques. Their catalytic behavior evaluated in the malic acid oxidative decarboxylation reaction underlined the importance of the incorporation of Mo into the structure of iron cobaltite and cobalt ferrite catalysts. The catalysts with the highest molybdenum content forming cobaltite and iron molybdate phases showed better activity, with cobaltite-based catalysts being more active than ferrite-based ones. [Display omitted] • The synthesis method - influences the phase composition of Mo-doped iron cobaltite and cobalt ferrite. • The cobaltite - improves the oxidative decarboxylation of malic acid. • Mo has a positive influence on the catalytic activity. • Replacement of cobalt and iron with molybdenum is beneficial for catalytic activity. [ABSTRACT FROM AUTHOR]

Highly efficient and direct photocatalytic H 2 evolution from water via water splitting without using sacrificial reagents is a challenging approach to convert solar energy into renewable and storable chemical energy. Herein, by amalgamating the architecture recommendations and energy band engineering principles into the design formulation, a novel Ag@CoFe 2 O 4 /g-C 3 N 4 plasmonic p-n heterojunction photocatalytic system is designed and constructed for the first time. The Ag@CoFe 2 O 4 /g-C 3 N 4 photocatalyst so designed, under the illumination of the visible-light (λ > 420 nm), produced H 2 and O 2 in 2:1 stoichiometric amount at the rates of 335 μmol h−1 and 186 μmol h−1, respectively, with an apparent quantum yield reaching 3.35% at 420 nm, demonstrating that Ag@CoFe 2 O 4 dimer colloids are responsible for oxidation and g-C 3 N 4 for reduction. Moreover, in the presence of triethanolamine, the apparent quantum yield achieved by Ag@CoFe 2 O 4 /g-C 3 N 4 is 16.47% with hydrogen produced at the rate 3.5 times higher than the CoFe 2 O 4 /g-C 3 N 4 heterojunction photocatalyst with AQY of 5.49%. The combination of Ag plasmonic effect and internal electric field established at the interface of p-type CoFe 2 O 4 and n-type g-C 3 N 4 boosts the separation efficiency of photoexcitons from CoFe 2 O 4 to g-C 3 N 4 , extending the visible-light absorption capacity of the systems. The generation of optimum amount of defects like oxygen vacancies at the p-n heterojunction interface due to the structural distortion of CoFe 2 O 4 also plays a prominent photocatalytic enhancement by providing active sites for the adsorption of water molecules for the light driven catalytic reactions. Our work introduces a potential avenue to design efficient photocatalysts by constructing several other suitable p-n heterojunction semiconductor photocatalysts toward practical application in solar energy conversion. Possible charge transfer mechanism in Ag@CFO/CN plasmonic p-n heterojunction photocatalyst. [Display omitted] • Design and construction of plasmonic Ag@CoFe 2 O 4 /g-C 3 N 4 p-n heterojunction photocatalysts. • Effect of Ag nanoparticles on the optic and electronic properties of CoFe 2 O 4 /g-C 3 N 4 heterojunction. • Impact of oxygen vacancies on the photocatalytic performance. • The charge separation is promoted by the p-n heterojunction. [ABSTRACT FROM AUTHOR]

In this work, a magnetodielectric coupling observed in barium titanate–cobalt ferrite composites synthesized using high-energy ball milling assisted via a thermal treatment is discussed. Vibrating sample magnetometry and dielectric spectroscopy showed that multiferroic composites possess both ferromagnetic and dielectric behaviors inherited from the parent ferromagnetic cobalt ferrite and ferroelectric barium titanate phases. The magnetocapacitance (up to 35%) recorded for x = 0.3, (1-x)BaTiO 3 –xCoFe 2 O 4 , can be attributed to the spin-dependent filtering mechanism. The composite with the aforementioned composition exhibited a homogeneous matrix–particle composite microstructure, which was achieved via high-energy ball milling during the mixing stage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cuboidal shaped CoFe 2 O 4 Nanoparticle powder synthesized using wet chemical synthesis technique. • High value of magnetic moment per formula unit confirms the partially inverse spinel crystal structure. • Optical properties studied through Diffuse Reflectance Spectroscopy of the nanopowder and SKM formalism. • Direct and indirect band gaps accurately determined by applying a detailed band gap estimation algorithm. Optical band gap of cuboidal Cobalt ferrite (CoF) Nanoparticles (NP), synthesized using wet chemical method, was accurately determined, by combining Diffuse Reflectance Spectroscopy (DRS) of the nanopowder, Schuster-Kubelka-Munk (SKM) formalism and the application of a detailed band gap estimation algorithm, using which absorption onsets and corresponding base line segments from the Tauc plots were precisely identified. Structural and compositional characterizations such as XRD, FE-SEM, TEM and EDX, were used to conclude that the NP exhibited cubic crystal structure with an average crystallite size of 14 nm. The values of indirect and direct band gaps were calculated to be 0.79 ± 0.01 eV and 1.5 ± 0.01 eV, respectively. The band gap shift for the nanocrystallites, from the bulk band gap, estimated using the effective mass model, came up to a value of 0.084 eV, which corresponded well to the experimentally obtained direct band gap of CoF NP. The direct and indirect band gap values were found to be well consistent with the partially inverse spinel crystal structure of the NP, emphasized using magnetization measurement. [ABSTRACT FROM AUTHOR]

Cobalt ferrite magnetic nanoparticles were synthesized and developed by a modified Pechini method using iron nitrate, cobalt nitrate, ethylene glycol (EG), and sucrose with different volumes of lemon juice (10, 20, 30, 40, 50, 60, and 70 ml) as the source of chelating agent as well as nonmagnetic elements such as Ca and Mg ions. The XRD patterns confirmed that all samples synthesized by different contents of extracted lemon juice had a cubic crystal structure with single-phase spinel. Scanning electron microscopy revealed that cobalt ferrite nanoparticles had a semi-spherical morphology. Also, the vibrating sample magnetometer indicated that the saturation magnetization of CoFe 2 O 4 nanoparticles prepared with different values of extracted lemon juice increased from 18.6 emu/g for 10 ml extracted lemon juice to 75.7 emu/g for 50 ml extracted lemon juice, after which the saturation magnetization diminished. Afterwards, the CoFe 2 O 4 nanoparticles were coated with polyethylene glycol (PEG) and doxorubicin (DOX) drugs, whereby drug delivery was detected at different pH levels. The CoFe 2 O 4 -PEG-DOX nanocomposite could release doxorubicin by more than 42% at pH = 5.4 in 75 h. [ABSTRACT FROM AUTHOR]

Underwater bubbling plasma (UBP) coupled with diatomite-CoFe 2 O 4 (Dt-CFO) activated peroxymonosulfate (PMS) was proposed for the degradation of ciprofloxacin hydrochloride (CIP) in this work. The catalyst sample of Dt-CFO with large specific surface area, rich active sites and excellent magnetic property was prepared by the hydrothermal method and systematically characterized to investigate its material properties. The combination of UBP and Dt-CFO activated PMS (UBP/Dt-CFO/PMS) showed excellent synergy with the synergistic factor of 1.98, and reached the CIP degradation percentage of 94.7%, which corresponded to the kinetic constant of 0.097 min−1. Dt-CFO with the diatomite content of 30 wt% achieved the best catalytic activity in the reaction system. Higher catalyst and PMS dose, peak voltage, pulse frequency and lower initial CIP concentration were beneficial for CIP removal. The addition of Cl−, HCO 3 −, SO 4 2− and humic acid suppressed CIP degradation, while NO 3 − had no effect on CIP removal. The Dt-CFO composite exhibited excellent reusability and low leaching metal amount, demonstrating its good stability. SO 4 −·, ·OH, ·O 2 −, 1O 2 , e aq , O 3 and H 2 O 2 were the active species confirmed to be involved in CIP degradation. The redox circles of ≡ Co(Ⅱ)/≡Co(Ⅲ) and ≡ Fe(Ⅱ)/≡Fe(Ⅲ) on Dt-CFO surface and the plasma-induced physicochemical effects dominated PMS activation. The decomposition process of CIP was explored through fluorescence spectra. Three degradation pathways were inferred, and the toxicity analysis showed the toxicity of CIP solution weakened after discharge treatment. [Display omitted] • A novel UBP/Dt-CFO/PMS method with excellent degradation performance was proposed. • Loading CoFe 2 O 4 on diatomite could provide more active species. • The Dt-CFO catalyst presented good stability and reusability. • Co/Fe valence conversion and plasma-induced phenomena dominated PMS activation. • ∙OH, SO 4 −·, ·O 2 −, 1O 2 and e aq were all involved in the degradation of the TCH. [ABSTRACT FROM AUTHOR]

This research focuses on the synthesis of nanoscale cobalt spinel ferrite (CoFe 2 O 4) via the sol-gel auto-combustion method and its integration with polyvinylidene fluoride (PVDF) to fabricate CoFe 2 O 4 -PVDF nanocomposites. The characterization of cobalt ferrite, using techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), revealed a pristine cubic spinel structure with a mean crystallite size of 46.61 nm, and a homogeneous particle distribution. A key finding is a marked reduction in AC conductivity upon incorporating CoFe 2 O 4 into the PVDF matrix, underscoring its potential in energy storage applications. The composite materials exhibit enhanced magnetic properties, including significant saturation magnetization and increased coercivity, making them prime candidates for high-density magnetic recording applications. Interestingly, the study also unveils that including CoFe 2 O 4 in PVDF does not alter the beta phase of PVDF, highlighting the compatibility and stability of the composite formation. Furthermore, the impedance analysis of the ferrite and composite samples revealed the predominance of grain boundary resistance, offering more profound insights into their electrical behaviour. This finding is pivotal in understanding the electrical conduction mechanisms within these nanocomposites. Despite the comprehensive analysis, the absence of the highest peak in the loss tangent indicates the necessity for further investigation into the dielectric loss dynamics of these materials. Overall, this research significantly advances the understanding of CoFe 2 O 4 nanostructures and their potential applications in advanced nanotechnology, particularly in energy storage and high-density magnetic recording. Future studies are expected to further refine these materials for a broader range of technological applications. • CoFe 2 O 4 Nanoparticle Synthesis - Used sol-gel auto-combustion to produce cobalt spinel ferrite. • Crystallite Size Determination - The average crystallite size of CoFe 2 O 4 was measured at 46.61 nm. • Characterization of PVDF- CoFe 2 O 4 Composites - Conducted detailed analysis of PVDF- CoFe 2 O 4 composites. • AC Conductivity Modulation with PVDF - Integration of PVDF resulted in reduced AC conductivity. • Significant Magnetic and Electric Properties were observed. [ABSTRACT FROM AUTHOR]

This research investigates the unique configuration of cobalt ferrite (Co 1.5 Fe 1.5 O 4) anchored onto the surface of cerium dioxide (CeO 2), which effectively activates peroxymonosulfate (PMS) to degrade trichloroethylene (TCE). Co 1.5 Fe 1.5 O 4 -CeO 2 /PMS was able to completely degrade 5 mg/L of TCE by comparison between PMS and the components of the prepared composites. In addition, the Co 1.5 Fe 1.5 O 4 -CeO 2 /PMS system was highly adaptable to pH and aqueous substrates. Quenching experiments combined with ESR spectroscopy results demonstrated that ·OH, SO 4 ·-, O 2 ·-, and 1O 2 in the system play an important role in degrading TCE. The Co 1.5 Fe 1.5 O 4 -CeO 2 /PMS system can maintain 90% degradation efficiency for various pollutants (TCE, carbon tetrachloride (CT), dichloromethane (DCM), 2,4-dichlorophenoxyacetic acid (2,4-D)) as well as the actual wastewater, and the multiple cycling experiments have verified that the Co 1.5 Fe 1.5 O 4 -CeO 2 /PMS has a good stability. XPS comparisons before and after the reaction revealed that cobalt ferrite exhibited a unique transition from the radical pathway to the non-radical pathway during TCE degradation after the introduction of CeO 2. This pathway shift can be attributed to the synergistic interaction between cobalt ferrite and CeO 2, which adjusts the electronic structure, facilitates the activation of PMS, and generates more reactive oxygen species to decompose TCE. This research offers valuable insights into the design of efficient advanced oxidation catalysts for the removal of organic pollutants from water and the optimization of degradation pathways. [Display omitted] • The Co 1.5 Fe 1.5 O 4 -CeO 2 /PMS system degraded 99% of TCE within 30 min under a wide range of pH conditions. • Trimetallic cycling in the system improves the decomposition efficiency of PMS and effectively reduces metal leaching. • With the introduction of CeO 2 , the process of TCE elimination changed from free radical dominated to a two-track system. • ●OH, SO 4 ●-, O 2 ●– and non-radical 1O 2 pathways all play important roles in TCE degradation in the system. [ABSTRACT FROM AUTHOR]

Mesoporous titanium silica-coated cobalt ferrite core-shell structures were synthesized as catalysts for styrene oxidation by hydrothermal and sol-gel methods. The catalysts were characterized by XRD, AA, SEM, TEM, FTIR spectroscopy, N 2 physisorption, ICP-OES and XPS. XRD patterns indicated that the magnetic core was composed of cobalt ferrite. SEM and TEM micrographs along with the IR spectra confirmed the presence as desired of a dense SiO 2 layer on the core. XPS revealed that the outest layer of the structure was made of a mesoporous Ti-SiO 2 layer. The successful incorporation of Ti active oxidation sites (framework Ti, FW Ti) in the mesoporous layer was verified by XPS Ti 2p spectra decomposition. The post-grafting method for the Ti insertion proved to be better than the one-pot to obtain a higher number of active Ti sites on the surface. All the synthesized catalysts were active in styrene oxidation with dilute aqueous H 2 O 2. The highest styrene conversion (37%) was obtained with the catalyst synthesized by post-grafting of Ti on a preformed mesoporous SiO 2 layer with a high specific surface area. This catalyst was the one with the highest fraction of surface FW Ti (XPS). The major products of the reaction were benzaldehyde and phenyl acetaldehyde. The catalyst was easily recovered from the reaction medium using an external magnet, and no significant loss of activity was observed after four catalytic cycles. [Display omitted] ● Successful synthesis of core-shell catalysts by hydrothermal and sol-gel methods. ● Titanium was inserted in the mesoporous layer mainly as isolated framework Ti. ● Ti-SiO 2 @CF and Ti/SiO 2 @CF catalysts are active in styrene oxidation. ● Benzaldehyde and phenyl acetaldehyde are the main oxidation products. ● Easy recovery of Ti/SiO 2 @CF from the reaction medium due to magnetic properties. [ABSTRACT FROM AUTHOR]

In this investigation, in order to enhance the properties of cobalt ferrite magnetic nanoparticles, apple pectin was utilized as a natural additive during the sol-gel auto-combustion technique. Differential thermal analysis (DTA) and thermogravimetric (TGA) curves revealed that the initial temperature of the combustion process drops when apple pectin is present, indicating that this additive improves combustion conditions. The X-ray diffraction (XRD) patterns demonstrated that a cubic spinel structure of pure cobalt ferrite nanoparticles was formed in the presence of apple pectin without the existence of a secondary phase. Additionally, the structural parameters, including the lattice parameters, average crystallite size, and cation distribution between the tetrahedral and octahedral sites, were determined using the Rietveld refinement method. All the synthesized samples exhibited a mixed spinel structure based on the investigation of the cation distribution. A decrease in particle size and nanoparticle agglomeration was observed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Moreover, the magnetic properties were investigated. According to the experimental findings, the presence of 0.3 g apple pectin increased the saturation/remanence magnetization and coercivity of cobalt ferrite nanoparticles. The improvement in magnetic properties was correlated with the average crystallite size, cation distribution, and magnetic moment of the cations occupying the octahedral/tetrahedral sites. In addition, the diffuse reflectance spectroscopy (UV–Vis-DRS) results showed that the energy of the band gap varies from 1.54 to 2.21 eV in the synthesized samples. [Display omitted] • CoFe 2 O 4 CFNPs were synthesized by sol-gel auto-combustion method in the presence of apple pectin agent. • The optimal amount of apple pectin was determined to achieve the best properties. • Structural properties of the synthesized CoFe 2 O 4 CFNPs were determined by Rietveld refinement method and TEM. • The effect of adding apple pectin on the magnetic and optical properties of the CoFe 2 O 4 CFNPs was investigated. [ABSTRACT FROM AUTHOR]

Cobalt ferrite nanoparticles (CFO NPs) were synthesized by a modified sol-gel method using Fe(NO 3) 3.9 H 2 O and Co(NO 3) 2 ·6H 2 O as the sources of Fe 3+ and Co 2+ in presence of different volumes of rosemary extract and sucrose as gel agent, chelating agent and non-magnetic elements such as calcium and magnesium ions. The prepared nanoparticles were characterized via X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The X-ray diffraction results confirmed that the sample prepared with 5 mL rosemary extract has single-phase spinel cobalt ferrite nanoparticles with a cubic crystal structure at 750 °C for 3 h (S1 sample). The average crystallite size was calculated about 33 nm using the Debye–Scherrer equation. Scanning electron microscopy also exposed that the prepared nanoparticles have a cubic morphology. Besides, the magnetic properties of the as-synthesized nanoparticles (S1 sample) indicated the highest saturated magnetization of 64 emu.g−1 as compared to other samples. The nanoparticles were then coated with tripolyphosphate (TPP) and chitosan polymer (Cs) to be applied as a carrier for drug delivery CoFe 2 O 4 -TPP-Cs (CFO-TPP-CS). The antioxidant doxorubicin (DOX) drug was then covered on the surface of the nanoparticles, and its drug release (CFO-TPP–CS–DOX) from the substrate of coated nanoparticles containing doxorubicin was evaluated at different pH levels. The coated CFO nanoparticles with tripolyphosphate (TPP) –Chitosan (Cs) sample indicated the biocompatibility and non-toxic nature of CFO-TPP- Cs NPs. Meanwhile, the CFO-TPP–CS–DOX nanosystem showed good death percentage of the breast cell cancer line (MCF-7 cell) in an acidic medium. Image 1 • CoFe2O4 NPs were obtained via sol-gel method in the presence of sucrose and rosemary extract as a novel green precursor. • Sucrose and rosemary extract play role as gel and chelating agents. •Effects of different volumes of rosemary on size and magnetic properties of NPs were investigated. • Chitosan (Cs) coated CoFe2O4 NPs served as nanocarrier and applied in loading and release of DOX. • The responsive CFO-Cs-TPP NPs are promising platform in drug delivery and cancer treatment applications. [ABSTRACT FROM AUTHOR]

In this work, cabon nanofiber supported cobalt ferrite composites (C/CFO) were prepared by electrospinning combined with hydrothermal method. The morphology, structure and microwave absorption properties were discussed in detail. The results revealed that the C/CFO composites with 3 D network structure exhibited excellent microwave absorption properties, which were linked to the composite compositions and synergistic effect between C NFs and CFO NPs. When the content of CFO NPs was 10 wt %, the C/CFO sample showed RL max of −137 dB at 11.36 GHz and the EAB (RL < −10 dB) of 11.44 GHz (6.59 GHz–18 GHz), which were superior to single component absorbent. Therefore, the C/CFO composites are highly promising applications in military and civilian fields. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of the four-electron-proton coupled oxygen evolution reaction (OER) limits the efficiency of water splitting. Herein, Ni–S–CoFe 2 O 4 magnetic nanosheets supported on Ni Foam (Magn-Ni-S-CoFe 2 O 4 /NF) as highly active OER electrocatalysts are synthesized via an extremely simple magnetic-field guided co-electrodeposition strategy. With the application of magnetic fields, the flower-like structures consisting of numerous nanosheets are obtained. This special interconnected structure can effectively reduce the transfer resistance to electrons during catalysis. The ultra-thin amorphous Ni–S layer at the edge of well-defined crystalline CoFe 2 O 4 provides more active sites for the reaction because of the abundant defects, which greatly enhances the OER performance. At the same time, the application of magnetic fields changes the chemical state of the electrocatalyst. The well-designed Magn-Ni-S-CoFe 2 O 4 /NF exhibits excellent OER activity with a low overpotential of 228 mV at the current density of 10 mA cm−2, which is lower than the value of 253 mV for the Ni–S–CoFe 2 O 4 /NF without applied magnetic field, a small Tafel slope of 72 mV dec−1 and excellent stability for at least 24 h. This work provides a simple magnetic field-assisted synthesis method to prepare electrocatalysts with excellent OER activity. • A new highly active and cost-effective electrocatalyst: Magn-Ni-S-CoFe 2 O 4 /NF. • An innovative synthesis method: electrodeposition assisted by magnetic field. • A excellent electrocatalytic activity of OER: 228 mV/10 mA cm−2 in 1 M KOH. [ABSTRACT FROM AUTHOR]

In this experimental study, the synthesis of cobalt ferrite nanoparticles, one of the most important types of ferromagnetic spinel ferrite materials was realized by using a method known as microwave assisted combustion method. The effects of the substance used as fuel on the structural, morphological, magnetic and photocatalytic properties of synthesized nanoparticles were investigated. Firstly, samples were prepared using urea, glycine and citric acid as fuel and then the samples were comprehensively characterized by advanced analysis techniques such as XRD, FT-IR, TEM, SEM, VSM, BET. Moreover, the usability of the obtained nanoparticles in photocatalytic degradation process of Procion Yellow H-E3G textile dye as photocatalyst was investigated. The results obtained indicate that the fuel used is highly effective on various properties of the synthesized materials. From the experiments performed to evaluate the photocatalytic performances of the nanoparticles, it was observed that each of the three different fuel matters used for the synthesis of nanoparticles were highly effective on the photocatalytic degradation of the organic pollutant. Furthermore, almost all the dye content in solution was completely removed at the end of the experimental period which lasted for 90 min. [ABSTRACT FROM AUTHOR]

• CoFe 2 O 4 synthesized presented a good performance in the photo-Fenton reaction. • The sodium diclofenac was 100% degraded and 86% of mineralization was obtained. • A mechanism based on the generation of OH groups is suggested. Emerging pollutants, among them pharmaceutical compounds, are found in surface and ground waters, suggesting their ineffective removal by conventional wastewater treatment technologies. In this paper, the removal of sodium diclofenac, a widely used non-steroidal anti-inflammatory drug, was explored by a heterogeneous Photo-Fenton process using CoFe 2 O 4 , H 2 O 2 and Uv germicide radiation (254 nm). Cobalt ferrites, were obtained by Pechini method and calcined at 600 °C and 800 °C. They were characterized by X-ray diffraction, Uv visible spectroscopy, Mössbauer and X-ray photoelectron spectroscopy, temperature-programmed reduction and specific surface area. The inverse spinel structure was obtained, and both materials presented good performance in the photo-Fenton reaction. A degradation mechanism based on the generation of OH groups is suggested. The complete sodium diclofenac degradation and 86% of mineralization of the total organic carbon were obtained using cobalt ferrite calcined at 800 °C. This catalyst was used in three cycles, without activity loss showing a negligible Fe leaching. [ABSTRACT FROM AUTHOR]