Mixed phase Fe2O3/Mn3O4 magnetic nanocomposite for enhanced adsorption of methyl orange dye: Neural network modeling and response surface methodology optimization

In this research, a novel magnetic mesoporous adsorbent with mixed phase of Fe₂O₃/Mn₃O₄ nanocomposite was prepared by a facile precipitating method and characterized extensively. The prepared nanocomposite was used as adsorbent for toxic methyl orange (MO) dye removal from aqua matrix considering its high surface area (178.27 m²/g) with high saturation magnetization (23.07 emu/g). Maximum dye adsorption occurs at solution pH 2.0 and the electrostatic attraction between anionic form of MO dye molecules and the positively charged nanocomposite surface is the main driving force behind this adsorption. Response surface methodology (RSM) was used for optimizing the process variables and maximum MO removal of 97.67% is obtained at optimum experimental condition with contact time, adsorbent dose and initial MO dye concentration of 45 min, 0.87 g/l and 116 mg/l, respectively. Artificial neural network (ANN) model with optimum topology of 3–5–1 was developed for predicting the MO removal (%), which has shown higher predictive ability than RSM model. Maximum adsorption capacity of this nanocomposite was found to be 322.58 mg/g from Langmuir isotherm model. Kinetic studies reveal the applicability of second‐order kinetic model with contribution of intra‐particle diffusion in this process.     

磁性壳聚糖/Fe3O4/氧化石墨烯吸附剂的制备及其多染料吸附性能

为了提高壳聚糖的多染料吸附性能并使其便于固液分离,采用共沉淀法制备了壳聚糖、磁铁矿纳米颗粒、氧化石墨烯复合磁性吸附剂(CS/Fe₃O₄/GO)。系统的结构表征显示,CS包覆的Fe₃O₄磁性纳米颗粒均匀地分布在GO的表面。CS/Fe₃O₄/GO具有高达42.5 emu·g-1的室温铁磁性,因此可在外加磁场中实现高效固液分离。研究表明,CS/Fe₃O₄/GO对亚甲基蓝(MB)、甲基橙(MO)和刚果红(CR)等多种染料具有良好的吸附性能,溶液的pH、初始浓度和吸附时间对其多染料吸附性能具有显著影响。在最佳条件下,CS/Fe₃O₄/GO对MB、MO和CR的吸附量分别达到210.6、258.6和308.9 mg·g-1。CS/Fe₃O₄/GO具有优异的循环利用性能,经5次循环后仍能保留90%以上的原始吸附量。采用吸附等温线和吸附动力学对...     

磁性壳聚糖/Fe3O4/氧化石墨烯吸附剂的制备及其多染料吸附性能

为了提高壳聚糖的多染料吸附性能并使其便于固液分离,采用共沉淀法制备了壳聚糖、磁铁矿纳米颗粒、氧化石墨烯复合磁性吸附剂(CS/Fe₃O₄/GO)。系统的结构表征显示,CS包覆的Fe₃O₄磁性纳米颗粒均匀地分布在GO的表面。CS/Fe₃O₄/GO具有高达42.5 emu·g^-1的室温铁磁性,因此可在外加磁场中实现高效固液分离。研究表明,CS/Fe₃O₄/GO对亚甲基蓝(MB)、甲基橙(MO)和刚果红(CR)等多种染料具有良好的吸附性能,溶液的pH、初始浓度和吸附时间对其多染料吸附性能具有显著影响。在最佳条件下,CS/Fe₃O₄/GO对MB、MO和CR的吸附量分别达到210.6、258.6和308.9 mg·g^-1。CS/Fe₃O₄/GO具有优异的循环利用性能,经5次循环后仍能保留90%以上的原始吸附量。采用吸附等温线和吸附动力学对CS/Fe₃O₄/GO的多染料吸附性能进行了拟合分析,并详细讨论了其吸附机理。     

Adsorption characteristics of Titan yellow and Congo red on CoFe2O4 magnetic nanoparticles

This paper assesses the adsorption characteristics of Titan yellow and Congo red on CoFe₂O₄ magnetic nanoparticles. The adsorption behavior of Titan yellow and Congo red from aqueous solution onto CoFe₂O₄ magnetic nanoparticles has been determined by investigating the effects of pH, concentration of the dye, amount of adsorbent, contact time, ionic strength and temperature. Experimental results indicated that CoFe₂O₄ nanoparticles can remove more than 98 % of each dye under optimum operational conditions of a dosage of 15.0 mg CoFe₂O₄, pH 3.0, initial dye concentration of 22–140 mg L^?1, and contact times of 2.0 and 15.0 min for Congo red and Titan yellow, respectively. Langmuir and Freundlich isotherm models have been used to evaluate the ongoing adsorption kinetic equations. Regeneration of the saturated adsorbent was possible by NaCl/acetone solution as eluent. The maximum adsorption capacities were 200.0 and 212.8 mg dye per gram adsorbent for Congo red and Titan yellow, respectively. With the help of adsorption isotherm, thermodynamic parameters such as free energy, enthalpy and entropy have been calculated. On the basis of pseudo-first-order and pseudo-second-order kinetic equations, different kinetic parameters have been obtained.     

Removal performance and mechanism of Fe3O4/graphene oxide as an efficient and recyclable adsorbent toward aqueous Hg(II)

Decontamination of aqueous heavy metal is a challenging task of environmental remediation. Herein, we demonstrated an adsorptive method for efficient removal of aqueous Hg(II) using a magnetic nanocomposite Fe₃O₄/graphene oxide (Fe₃O₄/GO). Adsorption of Hg(II) onto Fe₃O₄/GO equilibrated in 4 min, with the adsorption percent and quantity of 91.17% and 547.01 mg g^?1, respectively. Fe₃O₄/GO can be easily recovered from solution via magnetic separation for reuse, and retaining 73.5% of its original capacity after five consecutive cycles. The Temkin model and PSO model were most suitable for describing adsorption in equilibrium and non-equilibrium state, respectively. Both GO and Fe₃O₄ adsorbed Hg(II) via donating electrons in oxygen atoms toward Hg(II). Moreover, GO made a major contribution, while Fe₃O₄ made a minor one to adsorption. The facile preparation, high adsorption efficiency, easy recovery, and reusability may enable Fe₃O₄/GO to be a promising adsorbent for aqueous Hg(II).

     

Polyaniline/CoFe2O4 nanocomposite inhibits the growth of Candida albicans 077 by ROS production

In recent years, polyaniline/CoFe₂O₄ nanocomposites have gained attention because of their wide utilization in optoelectronics and biomedical studies. However, very limited research has been carried out on the anticandidal activity of polyaniline/CoFe₂O₄ nanocomposite against Candida spp. Thus, the study was designed to investigate the anticandidal potential of PANI/CoFe₂O₄ nanocomposite against Candida albicans 077. PANI/CoFe₂O₄ nanocomposite (denoted as “cfPNCs”) was synthesized by polymerization of aniline in the presence of CoFe₂O₄ nanoparticles. The structural and thermal properties of the synthesized PANI/CoFe₂O₄ nanocomposite were investigated. It was noteworthy that PANI/CoFe₂O₄ nanocomposite showed promising anticandidal activity in a dose-dependent manner. Results also showed that the protection of histidine (a ROS quencher) against ROS clearly suggested the implication of ROS in anticandidal activity of PANI/CoFe₂O₄ nanocomposite. It is encouraging to conclude that PANI/CoFe₂O₄ nanocomposite bears the potential of their applications in biomedicine, especially nanotherapy for diseases caused by C. albicans.     

Synthesis and characterization of CDs/Al2O3 nanofibers nanocomposite for Pb2+ ions adsorption and reuse for latent fingerprint detection

This study reports a new approach of preparation of carbon dots coated on aluminum oxide nanofibers (CDs/Al₂O₃NFs) nanocomposite and reusing the spent adsorbent of lead (Pb²⁺) ions loaded adsorbent (Pb²⁺-CDs/Al₂O₃NFs) nanocomposite for latent fingerprint detection (LFP) after removing Pb²⁺ ions from aqueous solution. CDs/Al₂O₃NFs nanocomposite was prepared by using CDs and Al₂O₃NFs with adsorption processes. The prepared nanocomposite was then characterized by using UV–visible spectroscopy (UV–visible), Fourier transforms infrared spectroscopy (FTIR), Fluorescence, X-ray diffraction pattern (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Zeta potential, X-ray photoelectron spectroscopy (XPS). The average size of the CDs was 51.18 nm. The synthesized CDs/Al₂O₃NFs nanocomposite has proven to be a good adsorbent for Pb²⁺ ions removal from water with optimum pH 6, dosage 0. 2 g/L. The results were best described by the Freundlich Isotherm model. The adsorption capacity of CDs/Al₂O₃NFs nanocomposite showed the best removal of Pb²⁺ ions with q_m = (177. 83 mg/g), when compared to the previous reports. This adsorption followed the pseudo-second order kinetic model. ΔG and ΔH values indicated spontaneity and the endothermic nature of the adsorption process. CDs/Al₂O₃NFs nanocomposite therefore showed potential as an effective adsorbent. The data were observed from adsorption–desorption after 6 cycles which showed good adsorption stability and re- usability of CDs/Al₂O₃NFs nanocomposite. Furthermore, the spent adsorbent of Pb²⁺-CDs/Al₂O₃NFs nanocomposite has proven to be sensitive and selective for LFP detection on various porous substrates. Hence Pb²⁺-CDs/Al₂O₃NFs nanocomposite can be reused as a good fingerprint labelling agent in LFP detection so as to avoid secondary environmental pollution by disposal of the spent adsorbent.     

CoFe2O4@Methylcellulose/AC as a New,Green, and Eco-friendly Nano-magnetic adsorbent for removal of Reactive Red 198 from aqueous solution

Methylcellulose (MC) is the most common commercial cellulose ether and the most attractive biopolymer due to its cheap cost of biodegradability, biocompatibility, hydrophilicity, and lack of toxicity. In this study, CoFe₂O₄@MC/activated carbon (AC) was synthesized as a unique magnetic nano-adsorbent in the presence of MC biopolymer for Reactive Red 198 (RR198) dye removal. The nano-magnetic adsorbent was characterized by FESEM (Field emission scanning electron microscopy), EDS (Energy-dispersive X-ray spectroscopy), Mapping, Linescan, BET (Brunauer–Emmett–Teller), FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffraction), and VSM (Vibrating-Sample magnetometer). For simple separation by external magnetic fields, the Ms value was 57.91 emu/g. According to XRD analysis, the nano-adsorbent maintains its crystal structure, with an average crystal size of 11 nm. The maximum removal efficiencies of RR198 for synthetic and real wastewater samples under optimal conditions (an initial concentration of 10 mg/L, pH 3, contact time of 10 min, nanocomposite dose of 1.5 g/L, and a temperature of 25 °C) were 92.2% and 78%, respectively. The adsorption experiments were fitted well with the Freundlich isotherm (R² = 0.989) and pseudo-second-order kinetic (R² = 0.995). The values of entropy changes (ΔS = 35.087 kJ/mol.k), enthalpy changes (ΔH = -9.862 kJ/mol), and negative Gibbs free energy changes (ΔG) showed that the adsorption process was exothermic. Finally, the reusability findings showed that after six recovery cycles, the efficiency decreased slightly (90.1%). In the end, it can be concluded that the prepared CoFe₂O₄@Methylcellulose/AC can be used as an efficient adsorbent for the removal of RR198 from an aqueous solution.     

Poly(butyl methacrylate)-grafted alginate/Fe3O4 nanocomposite: Synthesis and its application for removal of dyes

This study involved the utilization of a free radical-graft copolymerization reaction for the development of a novel adsorbent, namely, poly(butyl methacrylate)-grafted alginate/Fe₃O₄ nanocomposite (PBMA-gft-Alg/Fe₃O₄). Transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction patterns analysis, and Fourier transform infrared spectroscopy (FT-IR) were carried out for the characterization of Fe₃O₄ NPs and PBMA-gft-Alg/Fe₃O₄ nanocomposites. The capability of nanocomposites and nanoparticles to adsorb dyes such as MG and MB, resulting in their removal from aqueous media, was evaluated under different conditions such as pH, temperature, contact time, and dose of adsorbent. Optimum parameters for adsorption of dyes were found to be pH of 10, 50°C, contact time of 180 min, and 0.2 g of adsorbent. Efficiency of the PBMA-gft-Alg/Fe₃O₄ nanocomposite was found to be significantly greater than that of Fe₃O₄ NPs for eliminating the desired dye. Langmuir, Freundlich, Sips, and Temkin models were used for testing the experimental data. Freundlich model was the one that best described the adsorption.     

Preparation of magnetic separable CoFe2O4/PAC composite and the adsorption of bisphenol A from aqueous solution

CoFe₂O₄/PAC composite adsorbent has been prepared via an immersing-calcination process, using ethylene diamine tetraacetic acid (EDTA) and citric acid (CIT) ligands containing sol as the CoFe₂O₄ precursor. The microstructure characterization and magnetic property of as-prepared sample were performed by means of XRD and VSM measurements. The adsorption kinetics, isotherms and thermodynamic process toward Bisphenol A molecules (BPA, which is considered as one of the typical endocrine disrupting chemicals) occurred on as-prepared magnetic adsorbent which were investigated by the pseudo-second order kinetic/intraparticle models, the Langmuir/Freundlich adsorption isothermal models and basic chemical thermodynamics principles, respectively.     

Characterization and magnetic exchange observation for CoFe2O4–CoFe2 nanocomposite microfibers

The magnetic hard-soft CoFe₂O₄–CoFe₂ nanocomposite microfibers have been synthesized by the sol–gel and partial reduction process, where CoFe₂O₄ ferrite is the hard phase with a grain size range from 43 to 62 nm and CoFe₂ alloy the soft phase with grain sizes around 30 nm. These nanocomposite microfibers exhibit the magnetization behavior like a single phase magnetic material, and the magnetic exchange coupling effects are observed between the hard and soft phases. The specific saturation magnetization of CoFe₂O₄–CoFe₂ nanocomposite microfibers shows an increase tendency with the increasing weight fraction of CoFe₂, while the coercivity is consequently reduced. The nanocomposite microfibers have a maximum remanence 51.7 Am²/kg when the phase contents of CoFe₂ around 28 wt% and CoFe₂O₄ about 72 wt%.     

Preparation of CoFe2O4@vacancy@mSiO2 core-shell composites for removal of organic pollutant in aqueous solution

CoFe₂O₄@[email protected]₂ magnetic composites with core-shell structure were prepared with a simple two-step route and used for removal of organic pollutant in aqueous solution. The as-prepared nanocomposites were characterized by Brunner?Emmet?Teller (BET) measurements, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometer (VSM). The adsorption performances of CoFe₂O₄@[email protected]₂ for Rhodamine B (RhB) were evaluated. The effects of initial dye concentration, adsorbent dosage, contact time, solution pH, temperature, ionic strength on dye adsorption were studied. Finally, four consecutive adsorption–desorption cycles were conducted to investigate the reusability of CoFe₂O₄@[email protected]₂. The results showed that CoFe₂O₄@[email protected]₂ could remove RhB in a wide pH range. Increasing ionic strength could enhance the adsorption capacity of CoFe₂O₄@[email protected]₂ for RhB. The adsorption equilibrium obeyed Freundlich isotherm model and the maximum adsorption capacity under optimal conditions could reach 172.34 mg/g. The adsorption process of RhB onto CoFe₂O₄@[email protected]₂ nanocomposites was very fast and kinetic process could be represented by pseudo-second-order kinetic model. Thermodynamic parameters suggested that the adsorption of RhB onto CoFe₂O₄@[email protected]₂ was spontaneous and exothermic in nature. Based on the above results, the synthesized CoFe₂O₄@[email protected]₂ could be used as an effective adsorbent for RhB removal.     

Decoration of MWCNTs with CoFe2O4 Nanoparticles for Methylene Blue Dye Adsorption

In the present work, a simple and viable method for producing multi-walled carbon nanotubes (MWCNTs) decorated with CoFe₂O₄ nanoparticles is presented. Chemical composition and crystal structure of the CoFe₂O₄/MWCNT composite was confirmed by X-ray diffraction measurements, while transmission electron microscopy was used to characterize the morphology and the distribution of nanocrystals in the composite. The obtained particles with relatively small diameter (about 14.9?nm) were found to be dispersed on the carbon nanotubes. The adsorption of methylene blue dye on CoFe₂O₄/MWCNT composites has been investigated. CoFe₂O₄/MWCNT composites show high adsorption capacity for methylene blue dye. Both Langmuir and Freundlich models describe the adsorption isotherms very well and the adsorption thermodynamic parameters (?G ⁰, ?H ⁰ and ?S ⁰) were calculated. The adsorption of methylene blue is generally spontaneous and thermodynamically favorable. The adsorption of methylene blue involves an endothermic process.     

Insight into the performance of novel kaolinite-cellulose/cobalt oxide nanocomposite as green adsorbent for liquid phase abatement of heavy metal ions: Modelling and mechanism

A cost-efficient kaolinite-cellulose/cobalt oxide green nanocomposite (Kao-Cel/Co₃O₄ NC) was successfully synthesized, and utilized as a promising material for removing Pb²⁺ and Cd²⁺ from aqueous solution. The fabricated nanocomposite has been characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy-energy dispersive X-ray, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller analysis. The batch methodology was exploited for optimization of process parameters and the optimized conditions were found to be adsorbent dosage (2.0 g/L), extraction time (50 min), initial concentration (60 mg/L), and initial solution pH (6). Kao-Cel/Co₃O₄ NC displayed excellent adsorption properties and achieved maximum saturation capacity (Q_m) of 293.68 mg Pb²⁺/g and 267.85 mg Cd²⁺/g, with an equilibration time of 50 min at 323 K. The Langmuir model best expressed the isotherm data recommending the adsorption onto energetically homogeneous NC surface, while the compatibility of kinetics data with pseudo-second-order model revealed the dependency of adsorption rate on adsorption capacity, and probable involvement of chemisorption in the rate-controlling step. Electrostatic interaction and ion exchange mechanism were responsible for the uptake of Pb²⁺ and Cd²⁺ by Kao-Cel/Co₃O₄ NC as demonstrated by Fourier transform infrared spectroscopy and pH studies. Thermodynamic parameters confirmed the physical, spontaneous, and endothermic sequestration processes. Real water investigation specified that the present adsorbent could be effectively used for liquid phase decontamination of Pb²⁺ and Cd²⁺. The nanocomposite exhibited high reusability, which could be utilized efficiently for five runs with sustainable results. In summary, this study portrayed the present nanocomposite as an emerging material for the adsorption of heavy metal ions particularly Pb²⁺ and Cd²⁺.     

Equilibrium and kinetic study of novel methyltrimethoxysilane magnetic titanium dioxide nanocomposite for methylene blue adsorption from aqueous media

Novel magnetic titanium dioxide nanoparticles decorated with methyltrimethoxysilane (Fe₃O₄@TiO₂‐MTMOS) were successfully fabricated via a sol–gel method at room temperature. The synthesized material was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, thermogravimetric analysis and vibrating sample magnetometry. The removal efficiency of the adsorbent was evaluated through the adsorption of methylene blue (MB) dye from water samples. The adsorption isotherm and kinetics were evaluated using various models. The Langmuir model indicated a high adsorption capacity (11.5 mg g^?1) of Fe₃O₄@TiO₂‐MTMOS. The nanocomposite exhibited high removal efficiency (96%) and good regeneration (10 times) compared to Fe₃O₄ and Fe₃O₄@TiO₂ at pH = 9.0. Based on the adsorption mechanism, electrostatic interaction plays a main role in adsorption since MB dye is cationic in nature at pH = 9, whereas the adsorbent acquired an anionic nature. The newly synthesized Fe₃O₄@TiO₂‐MTMOS can be used as a promising material for efficient removal of MB dye from aqueous media.     

Humic Acid Removal by Combining the Magnetic Property of Maghemite with the Adsorption Property of Nanosized Hydroxyapatite

Maghemite incorporated hydroxyapatite (HAP) nanocomposite was prepared by in situ precipitation of the calcium phosphate phase in an iron oxide colloidal suspension. The resultant nanocomposite was characterized by x-ray diffraction, Fourier transform infrared spectrometer, transmission electron microscope, N₂ adsorption analysis, and vibrating sample magnetometry. The potential of HAP/γ-Fe₂O₃ nanocomposite for HA adsorption from aqueous solution was evaluated by batch experiments and adsorption kinetic tests. HA adsorption amount on the adsorbent decreased with increasing solution pH and the presence of KNO₃ and alkali-earth metal ions resulted in enhanced HA adsorption. HA adsorption onto HAP/γ-Fe₂O₃ nanocomposite could be well described by Freundlich and Sips models, while HA adsorption process on the adsorbent obeyed pseudo-second-order kinetics and the adsorption rates decreased with increasing initial HA concentration. This study showed that the HAP/γ-Fe₂O₃ nanocomposite could be used as an efficient and magnetically separable adsorbent for the removal of HA from aqueous solution. Subsequent studies demonstrated that the HA-loaded HAP/γ-Fe₂O₃ nanocomposite could be further applied for the highly efficient adsorption of methylene blue (MB) and separated from the medium by a simple magnetic process.     

GO/Fe3O4/有机胺复合材料的制备及对结晶紫染料的吸附性能

用改进的Hummers法制备了氧化石墨烯,用乙二胺、乙二胺与丁二胺/己二胺混溶来改性氧化石墨烯。用水热法制备了Fe3O4,并用物理混合法制备了GO/Fe3O4/有机胺的三元复合体系。用透射电镜、扫描电镜、红外光谱、热重分析、X射线衍射、VSM和XPS等对所制得的样品进行了结构表征和性能测试,研究了三元复合粒子对结晶紫染料的吸附性能及影响结晶紫染料吸附效果的因素。结果表明:所制备的Fe3O4的平均粒径约为200 nm,粒径分布均匀;复合物中GO为典型的片状结构,GO及有机胺的掺杂没有影响Fe3O4的尖晶石结构;复合物为超顺磁性,Ms为53.0 emu·g~(-1)。吸附结果表明:石墨烯/Fe3O4/有机胺的三元复合材料对结晶紫染料的最大吸附量随浓度增大而增大,而吸附结晶紫染料的移除率却随结晶紫染料浓度增大而减小,并趋向一定值;乙二胺和己二胺混溶比例为5∶1的GO/Fe3O4复合材料吸附性能最佳:结晶紫浓度为400 mg·L~(-1),最大吸附量为164.3 mg·L~(-1)。     

Nanostructured spinel-type M(M = Mg,Co, Zn)Cr2O4 oxides: novel adsorbents for aqueous Congo red removal

Nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides with novel adsorbents for aqueous Congo red removal were synthesized by a polyacrylamide gel method and studied for their phase structure, microstructure, adsorption performance, and multiferroic behavior. The phase structure and purity analysis revealed that the nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides presented a spinel-type cubic structure, and the formation of a secondary phase such as Cr₂O₃, MgO, ZnO, or Co₃O₄ was not observed. The microstructure characterization confirmed that the spinel-type MCr₂O₄ oxides grew from fine spherical particles to large rhomboid particles. Adsorption experiments of spinel-type MCr₂O₄ oxides for adsorption of Congo red dye were fitted well with the pseudo-second-order kinetics. The adsorption capacity of the ZnCr₂O₄ oxide (44.038 mg/g, pH 7, temperature 28 °C, initial dye concentration 30 mg/L) was found to be higher than that of MgCr₂O₄ oxide (43.592 mg/g, pH 7, temperature 28 °C) and CoCr₂O₄ oxide (28.718 mg/g, pH 7, temperature 28 °C). The effects of initial adsorbent concentration, initial dye concentration, pH, and temperature between the ZnCr₂O₄ oxide and Congo red dye at which optimal removal occurs, were performed. The thermodynamic studies confirmed that a high temperature favors the adsorption of Congo red dye onto ZnCr₂O₄ oxide studied. The nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides that exhibited high adsorption performance for adsorption of Congo red dye can be ascribed to the synergistic effect of electrostatic interaction, pore filling, and ion exchange. The present work suggested that the nanostructured spinel-type M(M = Mg, Co, Zn)Cr₂O₄ oxides have excellent adsorption performance and multiferroic behavior, which shows potential applications for removal of the Congo red dye from wastewater, magnetic memory recording media, magnetic sensor, energy collection and conversion device, and read/write memory.