Cobalt Ferrite Particles Research Articles

Durably Superhydrophobic Magnetic Cobalt Ferrites for Highly Efficient Oil-Water Separation and Fast Microplastic Removal.

Microplastic pollution has become a primary global concern in the 21st century. Recyclable magnetic particles with micro-nanostructures are considered an efficient and economical way to remove microplastics from water. In this study, superhydrophobic magnetic cobalt ferrite particles were prepared by using a simple coprecipitation method combined with surface functionalization. The micromorphology, chemical composition, hysteresis loop, and surface contact angle of the functionalized cobalt ferrite were characterized. The separation efficiency and absorption capacity of cobalt ferrite particles in water-oil separation and microplastic removal were investigated. The results showed that the saturation magnetic field intensity of cobalt ferrite was 65.52 emu/g, the residual magnetization intensity (Mr) was 18.79 emu/g, and the low coercivity was 799.83 Oe. Cobalt ferrites had stable superhydrophobicity in the pH range of 1-13. The separation efficiency of cobalt ferrite powder for four oil-water mixture separations was higher than 94.2%. The separation efficiency was as high as 99.6% in the separation of the hexane and water mixtures. Due to the synergistic effect of the hydrophobic effect and van der Waals force, the functionalized magnetic cobalt ferrite had a high and stable microplastic removal efficiency and capture capacity. The removal efficiency of microplastics was close to 100%, and the capture capacity was 2.56 g/g. After ten microplastic removal cycles, the removal efficiency reached more than 98%, and the surface contact angle was still greater than 150°.

Rational design of Boerhavia diffusa derived CoFe2O4-Carbon dots@Boehmite platform for photocatalysis and ultra trace monitoring of hazardous pesticide and UO22+ ions

In view of exploiting natural resources for designing of effectual materials in favor of detection and obliteration of water pollutants, a fluorescent nanomaterial (CDBHCF) based on biomass derived carbon dots (CDs) was constructed. The CDs and cobalt ferrite (CF) particles were anchored on boehmite (BH) which served as a support material for CDs. The CDBHCF nanocomposite was prepared via facile hydrothermal treatment for selective recognition of Methyl parathion (MP) pesticide and uranyl ions (UO22+). The corresponding structural, morphological and opto-electronic properties of the nanomaterials have been investigated by different physicochemical techniques. The fluorescent CDBHCF probe was employed to detect extremely low concentration of MP and UO22+ with detection limit of 22.4 nM and 4.4 nM, respectively. Ultimately, the proposed sensing platform was validated through real sample analysis. Besides, CDBHCF nanocomposite was utilized for photocatalytic abolition of Tetracycline (TC) in water samples. Initially, the impact of various operational parameters on the degradation efficiency, including catalyst dosage and initial pH were thoroughly examined. Under optimized conditions, the fabricated CDBHCF nanocomposite demonstrated excellent results for photocatalytic degradation of TC (92 % degradation in 120 min) under visible light illumination. Thus, the proposed strategy delivered an innovative insight for dual purpose of CDBHCF nanocomposite: as a fluorescent probe for real time monitoring and as a photocatalyst for removal of pollutants via simple photocatalytic degradation.

Нефарадеевское магнитоэлектричество в контексте мезомеханики

The paper outlines the physical basis of magnetoelectric conversion by means of the piezoelectric effect. The whole class of materials capable of such conversion is termed as multiferroics. An important group of those make composite media in which the ferromagnetic (or ferrimagnetic) and piezoelectric components dwell in close contact. The magnetic field, acting on the ferromagnet arises internal mechanical stresses via it, which are perceived by the other phase of the composite and launches the piezoelectric effect in it, i.e. makes the sample a source of potential difference. Whereas the ferromagnetic phase is always a solid substance, the piezophase can be not only a solid but also a polymer, and this expands considerably the application prospects of such convertors. Fundamental analysis shows that in a polymeric composite, ferromagnet particles under the action of an external field excite the piezoeffect in two ways simultaneously: through magnetostriction (change of the particle shape) and through a mechanical displacement of the particle body. Although these two methods are, in principle, independent, in a ferrite-polymer composite they always coexist, and under a given set of conditions their joint action might either enhance or reduce the conversion ef ficiency. This general conclusion is illustrated by the results of numerical modelling of the magnetoelectric effect in a composite film whose content mimics one of the currently best known polymer multiferroics: the dispersion of cobalt ferrite particles in a matrix of polyvinylidene fluoride (CFO-PVDF).

Removal of chromium(III) from contaminated waters using cobalt ferrite: how safe is remediated water to aquatic wildlife?

The release of hazardous elements by industrial effluents to aquatic ecosystems is a potential threat to the environment. Chromium (Cr) is one of the elements whose levels in several freshwater ecosystems should be reduced to promote water reuse. In recent years, magnetic materials have gained increasing interest as sorbents because of their easy removal from treated water through magnetic separation. In this study, colloidal cobalt ferrite (CoFe2O4) particles were investigated as magnetic sorbents for chromium-aqueous chemical species. The oxidative stress responses of Mytilus galloprovincialis mussels exposed to 200 μg/L of Cr, resembling remediated water, were evaluated. More than 95% of Cr was removed from contaminated solutions by CoFe2O4 aqueous suspensions at pH 6 and pH 10. The kinetics of sorption experiments were examined using pseudo-1st order, pseudo-2nd order and Elovich models to evaluate which mathematical model has a better adjustment to the experimental data. The present study revealed that the levels of Cr that remained in remediated water induced limited biochemical changes in mussels, being considered safe for aquatic systems. Overall, the use of cobalt ferrite–based sorbents may constitute a promising approach to remediate contaminated water.

Viscosity Anomalies of Magnetic Fluid Stabilized by a Double Layer of Surfactant in Water

Purpose to study the temperature dependence of the viscosity of a water-based magnetic fluid.Method. Consists of measuring the dynamic viscosity of a magnetic fluid based on cobalt ferrite particles stabilized in water by a double layer of surfactant. Lauric acid (first layer) and a mixture of lauric acid and sodium dodecyl sulfate (second layer) were used as a stabilizer. Measurements were performed using a Brookfield DV-II+Pro rotational viscometer equipped with a coaxial cylinder system. The measuring system of the viscometer was thermostated using a KRIO-VT-12-1 thermostat.Results. The temperature dependences of dynamic viscosity were measured for three samples of magnetic fluid based on cobalt ferrite particles of various concentrations in the temperature range 0–90C°. The obtained temperature dependences of viscosity are radically different from the temperature dependences both predicted by known theories and experimentally observed for kerosene-based magnetic fluids. According to well-known theoretical models, the ratio of the viscosity of the magnetic fluid to the viscosity of the base medium is a certain universal function of particle concentration. Different models offer different types of this feature. But it clearly follows from them that the viscosity ratio should not depend on temperature. For magnetic fluids based on kerosene, it has been experimentally established that its relative viscosity decreases with increasing temperature. However, according to the results obtained, the relative viscosity of a water-based magnetic fluid does not decrease with increasing temperature, but increases significantly. That is, the viscosity of a water-based magnetic fluid decreases more slowly with increasing temperature than the viscosity of water.Conclusion. The observed dependencies completely contradict the known patterns, both theoretical and experimentally established for kerosene-based magnetic fluids. The results obtained may be useful for the further development of the theory of aqueous colloidal solutions with particle stabilization by a double layer of surfactants.

Exploring pressure, temperature, and flow patterns in ciliated microfluidic systems

The integration of cilia-induced flow, nanofluids, and the inclusion of cobalt ferrite particles holds significant promise in fluid dynamics, heat transfer, and nanotechnology, offering potential breakthroughs in various technological and material applications. We explore the behavior of cilia-induced flow in a nanofluid confined within an annular domain, employing the Williamson fluid model to characterize the behavior of cobalt ferrite (CoFe2O4) nanoparticles. Our analysis is based on a mathematical treatment rooted in fundamental mass, momentum, and energy conservation principles while considering physical constraints (low Reynolds number and long wavelength) and adopting a dimensionless approach. By applying regular perturbation techniques, we derive series solutions for velocity and temperature profiles, providing insight into the complex interplay among cilia-generated flow, nanofluid properties, and the influence of Cobalt ferrite nanoparticles within the annular configuration. In particular, we uncovered clear correlations among cilia length, amplitude ratio, flow rate, and the Prandtl number with temperature distribution. Also, we observed substantial reductions in temperature trends under Weissenberg numbers and particle volume fractions.

Cobalt Ferrite Synthesized Using a Biogenic Sol–Gel Method for Biomedical Applications

Cancer is one of the leading causes of death worldwide. Conventional treatments such as surgery, chemotherapy, and radiotherapy have limitations and severe side effects. Magnetic hyperthermia (MH) is an alternative method that can be used alone or in conjunction with chemotherapy or radiotherapy to treat cancer. Cobalt ferrite particles were synthesized using an innovative biogenic sol–gel method with powder of coconut water (PCW). The obtained powders were subjected to heat treatments between 500 °C and 1100 °C. Subsequently, they were characterized by thermal, structural, magnetic, and cytotoxic analyses to assess their suitability for MH applications. Through X-ray diffraction and Raman spectroscopy, it was possible to confirm the presence of the pure phase of CoFe2O4 in the sample treated at 1100 °C, exhibiting a saturation magnetization of 84 emu/g at 300 K and an average grain size of 542 nm. Furthermore, the sample treated at 1100 °C showed a specific absorption rate (SAR) of 3.91 W/g, and at concentrations equal to or below 5 mg/mL, is non-cytotoxic, being the most suitable for biomedical applications.

Fabrication of negative magnetostrictive Japanese traditional paper (washi) with cobalt ferrite particles

The cellulose fibers that form washi are longer than those of regular paper made from wood pulp. Hence, the mechanical properties of washi can be higher than those of conventional paper. This study evaluated the magnetic, magnetostrictive, and tensile properties of negative magnetostrictive cobalt ferrite (CoFe2O4) particle dispersed handmade washi (washi−CoFe2O4). The CoFe2O4 additives magnetized the washi, which displayed negative magnetostriction with the fiber direction perpendicular to the magnetic field and in the parallel fiber direction. Concerning the mechanical properties, the washi−CoFe2O4 displayed an elongation of up to 77% after yielding.

Effect of Ce3+ on structural, morphological, dc electrical resistivity and magnetic studies of Co nano ferrites

The sol-gel auto-combustion method produced rare earth Ce3+ substituted Cobalt ferrite nanomaterials, CoFe2-xCexO4 (x = 0.0, 0.04, 0.08, and 0.12). An X-ray diffractometer, a Field effect scanning electron microscope, a Fourier transform infrared spectrometer, a DC electrical resistivity, and a vibrating sample magnetometer were used to investigate them. The structural, dc resistivity and magnetic properties were examined using standard techniques. XRD analysis revealed a cubic spinel structure in a single phase without any impurity phase for all the prepared samples. With increasing Ce3+ content, a decrease in crystallite size was observed according to Scherrer's formula. Grain size and surface morphology determined from FESEM analysis were 20 to 30 nm. The samples' cubic spinel ferrite properties may be seen in the FTIR data, which show two distinct absorption bands related to the octahedral site at 400 cm-1 and the tetrahedral site at 600 cm-1. FTIR also confirms the presence of Ce3+ in the crystal structure. As the Ce3+ content increases, the DC resistivity decreases, confirming the material's semiconducting nature and temperature increase in all the synthesized samples. The magnetic behaviour strongly influences the substitution of Ce3+ ions. The samples' paramagnetic properties are enhanced by saturation magnetization. The size of the particles affects their coercivity. For the use of nano cobalt ferrite particles in high-density recording media, the MS and HC can be modified.

An Effective Method of Magnetic Hyperthermia Based on the Ferromagnetic Resonance Phenomenon

Nickel and cobalt ferrite nanoparticles have been synthesized using the chemical precipitation method; the nanoparticle sizes were found to be 63 ± 22 and 26 ± 4 nm, respectively. The static hysteresis loops and Mössbauer spectra have been measured. It is shown that cobalt ferrite powders are magnetically harder than nickel ferrite powders. Ferromagnetic resonance (FMR) curves have been studied. It is found that the FMR absorption for cobalt ferrite is observed at room temperature and above. The time dependences of the nanoparticle warm-up under FMR conditions have been measured. The maximum temperature changes for nickel ferrite and cobalt ferrite particles are 8 and 11 K, respectively. Using the example of cobalt ferrite powder, the possibility of effectively heating of particles in the FMR mode in their own field without using a DC magnetic field source is shown. The observed effect can be used in magnetic hyperthermia.

Nano-ferrofluid (Mn–Zn, CoFe2O4, Fe3O4) flow in a permeable channel with induced magnetic field

This article deals with the magnetohydrodynamics (MHD) transportation of water-based nano-ferrofluid in a channel. Three different types of ferrofluid suspensions, to be specific, water-containing magnetite, cobalt ferrite, and manganese-zinc ferro particles (, , ) are taken to observe flow field, induced magnetic field, and temperature field. The non-dimensional mathematical model is solved numerically under the specified wall and free stream conditions. The key parameters emerging in the present model are Prandtl number, porosity, the reciprocal of magnetic Prandtl number and magnetic parameter. The impact of these parameters on the flow field, velocity, temperature, and gradient of magnetic stream function for various ferrofluid suspensions is discussed graphically. Altogether, a more prominent velocity of fluid is noticed for magnetite ferro particles as contrasted with cobalt or manganese-zinc ferro particles due to the lower density of magnetite ferro particles. It is observed that when the volume fraction of nanoparticle rises from 0.1 to 0.6, heat transfer at the lower wall of channel is increased by 11 and decreased by 36 at the upper wall of the channel.

Нарушение закона броуновской релаксации для частиц феррита кобальта в воде

In the temperature range 0–90°C, the dynamic susceptibility of three samples of a magnetic fluid based on cobalt ferrite particles stabilized in water with a double layer of a surfactant was meas-ured. The first layer of the stabilizer was formed of auric acid molecules. The second layer consisted of a mixture of lauric acid and sodium dodecyl sulfate. The liquid samples had a small (about 10%) volume fraction of particles in order to reduce the influence of interparticle interactions and eliminate non-Newtonian rheological properties. The main parameter in which the samples differed was viscosity. It was changed by adding a small amount of polyvinyl alcohol. For all samples, in the studied temperature range the frequency dependence of the dynamic susceptibility had a quasi-Debye form with a pronounced maximum for the imaginary part. The value of the magnetization relaxation time was determined from the frequency of the maximum on the imaginary part of the dynamic susceptibility. As a result, the dependences of themagnetization relaxation time on tem-perature were obtained. To analyze the results obtained, viscosities of the samples were measured. All samples exhibited the properties of Newtonian fluids –the value of dynamic viscosity did not depend on the shear rate. The obtained results on the dynamic susceptibility and viscosity were compared by plotting relaxation times as a function of the ratio ofdynamic viscosity to absolute temperature. The resulting dependences do not fit on one universal straight line, as it is supposed to be according to the theory. The actual graph looks like a family of three different curves that di-verge as viscosity increases. In order to assess the influence of Néel relaxation on the resulting sus-ceptibility, the dynamic susceptibility of a frozen sample of the magnetic fluid was measured. The resulting susceptibility value was about 3% of the initial susceptibility of the liquid sample. Thus, despite the insignificant contribution of the Néel mechanism of magnetization relaxation to the dy-namic susceptibility, it is impossible to explain the obtained measurement results on the basis of the Brownian relaxation mechanism alone.

Improvement of rheological and transient response of magnetorheological grease with amalgamation of cobalt ferrite

The time responsiveness of magnetorheological grease (MRG) towards magnetic field stimulus is crucial in order to ensure the high performance of MR devices. However, due to the thixotropic properties of grease, MRG has been restricted in terms of responding rapidly towards these magnetic fields. Therefore, polygonal shapes made up of 1–3 μm of cobalt-ferrite (CoFe2O4) particles with different concentrations from 0 to 5 wt.% were introduced to enhance the responsiveness of the MRG. The results revealed that the linear viscoelastic (LVE) region of the modified MRG improved between 29% and 43% during the off-state and on-state conditions, respectively. The absolute MR effect of MRG increased by at least 60% due to the improvement in the particle's chain alignment with that of the applied magnetic fields. In terms of transient responses, particularly within the highly acceptable LVE region (0.05%), the MRG with CoFe2O4 performed about 5–6 s faster as compared to pure MRG, which was attributed to the improvement in the particle's mobility in the grease medium.

Magnetic Nanosorbents Based on Bentonite and CoFe2O4 Spinel

New magnetic nanocomposite sorbents were obtained by doping natural bentonite with nanosized CoFe2O4 spinel (10 and 20 wt.%). Nanocrystals of cobalt ferrite were synthesized by a citrate burning method. The structure and physical-chemical properties of the composites were characterized by XRD, XRF, TEM, BET, FTIR and Faraday balance magnetometry. During the formation of nanocomposites, 10–30 nm particles of cobalt ferrite occupied mainly the interparticle space of Fe-aluminosilicate that significantly changed the particle morphology and composite porosity, but at the same time retained the structure of the 2:1 smectite layer. A combination of two functional properties of composites, adsorption and magnetism has been found. The adsorption capacity of magnetic nanosorbents exceeded this parameter for bentonite and spinel. Despite the decrease in the adsorption volume, pore size and specific surface area of the composite material relative to bentonite, the sorption activity of the composite increases by 12%, which indicated the influence of the magnetic component on the sorption process. FTIR data confirmed the mechanism of formaldehyde sorption by the composite sorbent. The production of a magnetic nanosorbent opens up new possibilities for controlling the sorption processes and makes it possible to selectively separate the sorbent from the adsorption medium by the action of a magnetic field.

Cobalt Ferrite Particles Produced by Sol-Gel Autocombustion and Embedded in Polysilane: An Innovative Route to Magnetically-Induced Fluorescence Composites.

Fluorescence detection is currently one of the commonly used techniques worldwide. Through this work, the preparation and optical properties of an interesting composite material are discussed. It is shown that encapsulating cobalt spinel ferrite (CoFe2O4), obtained by the sol-gel autocombustion method, into poly[diphenyl-co-methyl(H)]silane matrix leads to fluoromagnetic particles (PSCo) with intriguing optical properties. Transmission electron microscopy, combined with energy-dispersive X-ray analysis, showed 500 nm large spherical structures containing a core (around 400 nm in diameter) composed of magnetic ferrite particles, surrounded by a thin layer of semiconductive fluorescent polymer. The as-obtained material exhibited ferrimagnetic properties. The FTIR spectrum confirmed that the Si-H functionality of the polysilane was preserved. UV spectroscopy combined with molecular modeling studies indicated that the magnetic core had a strong influence on the intramolecular electron transitions characteristic of the σ-conjugated polysilane. Further analysis by steady-state fluorescence spectroscopy revealed that the internal magnetic field strongly enhances the polysilane emission. This property will be further investigated in the future in order to develop new detection devices.

Hardening of Cobalt Ferrite Nanoparticles by Local Crystal Strain Release: Implications for Rare Earth Free Magnets.

In this work, we demonstrate that the reduction of the local internal stress by a low-temperature solvent-mediated thermal treatment is an effective post-treatment tool for magnetic hardening of chemically synthesized nanoparticles. As a case study, we used nonstoichiometric cobalt ferrite particles of an average size of 32(8) nm synthesized by thermal decomposition, which were further subjected to solvent-mediated annealing at variable temperatures between 150 and 320 °C in an inert atmosphere. The postsynthesis treatment produces a 50% increase of the coercive field, without affecting neither the remanence ratio nor the spontaneous magnetization. As a consequence, the energy product and the magnetic energy storage capability, key features for applications as permanent magnets and magnetic hyperthermia, can be increased by ca. 70%. A deep structural, morphological, chemical, and magnetic characterization reveals that the mechanism governing the coercive field improvement is the reduction of the concomitant internal stresses induced by the low-temperature annealing postsynthesis treatment. Furthermore, we show that the medium where the mild annealing process occurs is essential to control the final properties of the nanoparticles because the classical annealing procedure (T > 350 °C) performed on a dried powder does not allow the release of the lattice stress, leading to the reduction of the initial coercive field. The strategy here proposed, therefore, constitutes a method to improve the magnetic properties of nanoparticles, which can be particularly appealing for those materials, as is the case of cobalt ferrite, currently investigated as building blocks for the development of rare-earth free permanent magnets.

Co-Precipitation Synthesis of MnFe2O4 and CoFe2O4 Nanoparticles

Nano-sized magnetic manganese ferrite, cobalt ferrite particles were produced by a co-precipitation method at room temperature. The effects of pH value of solutions, where the particles were synthesized, on the morphology and crystal structure of the MnFe 2 O 4 and CoFe 2 O 4 particles were investigated. The particles were pure and nearly spherical shaped. The sizes of synthesized magnetic nanoparticles had between 55 nm and 84 nm, with uniform morphologies. As the pH value increased, the diameter of the synthesized particles decreased and agglomeration of the nanoparticles increased. Keywords: cobalt ferrite, co-precipitation, manganese ferrite, nanoparticle DOI: 10.7176/CMR/14-3-03 Publication date: August 31 st 2022

Microfluidic Processing of Piezoelectric and Magnetic Responsive Electroactive Microspheres.

Poly(vinylidene fluoride) (PVDF) combined with cobalt ferrite (CFO) particles is one of the most common and effective polymeric magnetoelectric composites. Processing PVDF into its electroactive phase is a mandatory condition for featuring electroactive behavior and specific (post)processing may be needed to achieve this state, although electroactive phase crystallization is favored at processing temperatures below 60 °C. Different techniques are used to process PVDF-CFO nanocomposite structures into microspheres with high CFO dispersion, with microfluidics adding the advantages of high reproducibility, size tunability, and time and resource efficiency. In this work, magnetoelectric microspheres are produced in a one-step approach. We describe the production of high content electroactive phase PVDF and PVDF-CFO microspheres using microfluidic technology. A flow-focusing polydimethylsiloxane device is fabricated based on a 3D printed polylactic acid master, which enables the production of spherical microspheres with mean diameters ranging from 80 to 330 μm. The microspheres feature internal and external cavernous structures and good CFO distribution with an encapsulation efficacy of 80% and prove to be in the electroactive γ-phase with a mean content of 75%. The microspheres produced using this approach show suitable characteristics as active materials for tissue regeneration strategies and other piezoelectric polymer applications.

Facile Synthesis of Cobalt Ferrite (CoFe2O4) Nanoparticles in the Presence of Sodium Bis (2-ethyl-hexyl) Sulfosuccinate and Their Application in Dyes Removal from Single and Binary Aqueous Solutions.

A research study was conducted to establish the effect of the presence of sodium bis-2-ethyl-hexyl-sulfosuccinate (DOSS) surfactant on the size, shape, and magnetic properties of cobalt ferrite nanoparticles, and also on their ability to remove anionic dyes from synthetic aqueous solutions. The effect of the molar ratio cobalt ferrite to surfactant (1:0.1; 1:0.25 and 1:0.5) on the physicochemical properties of the prepared cobalt ferrite particles was evaluated using different characterization techniques, such as FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption analysis, and magnetic measurements. The results revealed that the surfactant has a significant impact on the textural and magnetic properties of CoFe2O4. The capacity of the synthesized CoFe2O4 samples to remove two anionic dyes, Congo Red (CR) and Methyl Orange (MO), by adsorption from aqueous solutions and the factors affecting the adsorption process, such as contact time, concentration of dyes in the initial solution, pH of the media, and the presence of a competing agent were investigated in batch experiments. Desorption experiments were performed to demonstrate the reusability of the adsorbents.

Synthesis of Magnetic Adsorbents Based Carbon Highly Efficient and Stable for Use in the Removal of Pb(II) and Cd(II) in Aqueous Solution.

In this study, two alternative synthesis routes for magnetic adsorbents were evaluated to remove Pb(II) and Cd(II) in an aqueous solution. First, activated carbon was prepared from argan shells (C). One portion was doped with magnetite (Fe3O4+C) and the other with cobalt ferrite (CoFe2O4+C). Characterization studies showed that C has a high surface area (1635 m2 g−1) due to the development of microporosity. For Fe3O4+C the magnetic particles were nano-sized and penetrated the material’s texture, saturating the micropores. In contrast, CoFe2O4+C conserves the mesoporosity developed because most of the cobalt ferrite particles adhered to the exposed surface of the material. The adsorption capacity for Pb(II) was 389 mg g−1 (1.88 mmol g−1) and 249 mg g−1 (1.20 mmol g−1); while for Cd(II) was 269 mg g−1 (2.39 mmol g−1) and 264 mg g−1 (2.35 mmol g−1) for the Fe3O4+C and CoFe2O4+C, respectively. The predominant adsorption mechanism is the interaction between -FeOH groups with the cations in the solution, which are the main reason these adsorption capacities remain high in repeated adsorption cycles after regeneration with HNO3. The results obtained are superior to studies previously reported in the literature, making these new materials a promising alternative for large-scale wastewater treatment processes using batch-type reactors.