MnFe2O4 Nanoparticles Research Articles

Development of watermelon rind derived activated carbon/manganese ferrite nanocomposite for cleaner desalination by capacitive deionization

Capacitive deionization (CDI) is one of the most efficient and emerging techniques for water desalination applications. This work reports the development, characterization and CDI studies of watermelon derived activated carbon (WMAC) and its MnFe2O4 composite (WMAC/MnFe2O4) for NaCl desalination. WMAC was prepared through single-step low-temperature pyrolysis by H3PO4 activation. Facile synthesis of spinel MnFe2O4 nanoparticles on WMAC surface was performed through the hydrothermal technique. Morphological, textural and physico/electro–chemical analysis showed the effect of MnFe2O4 incorporation on WMAC. The nanocomposite possessed definite crystallites, low structural disorders and sufficient magnetization for electrochemical applications. Also, the nanocomposite was dominantly composed of mesopores with a specific surface area of 483 m2/g. The high specific capacitance value of 425 F/g (scan rate – 10 mV/s) along with better stability and low charge resistance, confirmed the suitability of WMAC/MnFe2O4 as an efficient electrode material for CDI applications. NaCl removal studies using WMAC/MnFe2O4 showed an electrosorption capacity of 29.7 mg/g for the nanocomposite, with rapid desalination and good recyclability. A plausible mechanism of salt adsorption and desorption is also presented. WMAC/MnF2O4 exhibited significant application potential for the industrial desalination.

Manganese ferrite graphene nanocomposite synthesis and the investigation of its antibacterial properties for water treatment purposes

The main objective of this study was to synthesize a nanocomposite using graphene and manganese ferrite nanoparticles (MnFe2O4-G) and to evaluate its antibacterial activity for water treatment purposes. Its morphological characteristics were evaluated by instrumental techniques, such as scanning electron microscopy and transmission electron microscopy. The characterization results indicated that the nanocomposite presented nanoparticles of approximately 25 nm well dispersed in transparent and large (14 μm) graphene nanosheets. The antibacterial activity was evaluated in a batch experiment using a concentration of 40 μg mL-1 of nanocomposite (MnFe2O4-G, bare MnFe2O4 nanoparticles or graphene oxide), 1x105 CFU mL-1 of Escherichia coli, and 8 h of contact time at room temperature. The highest antibacterial capacity was observed for the hybrid nanocomposite (91.91%), due to the synergic effect of graphene and MnFe2O4 nanoparticles. Various mechanisms were proposed to explain the effective antibacterial activity of MnFe2O4-G, such as wrapping, oxidative stress, sharp-edge cutting effect, among others. The results showed that MnFe2O4-G is a potential alternative in water treatment processes as an antibacterial agent.

Judicious fabrication of bifunctionalized graphene oxide/MnFe2O4 magnetic nanohybrids for enhanced removal of Pb(II) from water

Novel ternary nanohybrids, bifunctionalized graphene oxide/MnFe2O4 magnetic nanoparticles (PEHA-Phos-GO/MnFe2O4), were prepared by a facile method and applied for the removal of Pb(II) from aqueous solution. Attributing to the numerous amino and phosphate groups on the bifunctionalized GO nanosheets as well as the magnetic nanoparticles of MnFe2O4, PEHA-Phos-GO/MnFe2O4 demonstrated high removal efficiency of Pb(II) and rapid magnetic separation. The 366.4 mg/g maximum adsorption capacity of Pb(II) on PEHA-Phos-GO/MnFe2O4 was obtained at the optimal adsorption pH of 5.5, much higher than that on GO (212.1 mg/g). The kinetics and isotherm data indicated that the adsorption processes can be well described by the pseudo-second-order kinetics and the Langmuir model. For the adsorption of Pb(II) on PEHA-Phos-GO/MnFe2O4, thermodynamic studies revealed the endothermic nature of the spontaneous adsorption process. The exhibited adsorption capacity, easy magnetic separation and reusability make the PEHA-Phos-GO/MnFe2O4 nanohybrids very promising adsorbents for efficacious removal of heavy metals from aqueous solutions in environmental pollution cleanup.

Effect of Additional MnFe<sub>2</sub>O<sub>4</sub> on a Combination of EG-Water Nanofluid and Volumetric Flowrate Variations towards Heat Transfer in Shell and Tube Heat Exchanger System

Nanofluid is an efficient fluid when used in heat exchanger system because of its larger thermal conductivity compared to conventional fluids such as water, oil, and ethylene glycol (EG). This research used MnFe2O4 nanoparticle due to its higher magnetic sensitivity compared to other ferrite nanoparticles and larger thermal conductivity than TiO2. This research used the MnFe2O4 nanoparticle with a combination of EG-Water base fluids in ratios of 40:60, 60:40, and 80:20. MnFe2O4 nanofluid mixed with EG-Water base fluids was made using the two-step method with 0.05% MnFe2O4 volume fraction in each base fluid ratio. This research used shell and tube type heat exchanger with heat temperature of 60°C and cold temperature of 26°C that were carried out at volumetric flowrate in each base fluid ratio for 0.22 l/m, 0.44 l/m, and 0.66 l/m. This research aimed to find the best combination ratio of EG-Water in thermophysical (thermal conductivity, specific heat, density, and viscosity) and to find the effect of volumetric flowrate variations on the heat exchange characteristics (the Reynold number, the Nusselt number, ∆T LMTD, convection coefficient, heat transfer, and overall heat transfer coefficient). The results of this research were that the sample of EG-Water with 40:60 ratio had the best heat transfer characteristics compared to samples with 60:40 and 80:20 ratios. Meanwhile, for the volumetric flow rate, a higher volumetric flow rate resulted in a larger result.

Incremental substitution of Ni with Mn in NiFe2O4 to largely enhance its supercapacitance properties

By using a facile hydrothermal method, we synthesized Ni1−xMnxFe2O4 nanoparticles as supercapacitor electrode materials and studied how the incremental substitution of Ni with Mn would affect their structural, electronic, and electrochemical properties. X-ray diffractometry confirmed the single-phase spinel structure of the nanoparticles. Raman spectroscopy showed the conversion of the inverse structure of NiFe2O4 to the almost normal structure of MnFe2O4. Field-emission scanning electron microscopy showed the spherical shape of the obtained nanoparticles with a size in the range of 20–30 nm. Optical bandgaps were found to decrease as the content of Mn increased. Electrochemical characterizations of the samples indicated the excellent performance and the desirable cycling stability of the prepared nanoparticles for supercapacitors. In particular, the specific capacitance of the prepared Ni1−xMnxFe2O4 nanoparticles was found to increase as the content of Mn increased, reaching the highest specific capacitance of 1,221 F/g for MnFe2O4 nanoparticles at the current density of 0.5 A/g with the corresponding power density of 473.96 W/kg and the energy density of 88.16 Wh/kg. We also demonstrated the real-world application of the prepared MnFe2O4 nanoparticles. We performed also a DFT study to verify the changes in the geometrical and electronic properties that could affect the electrochemical performance.

Carbon-encapsulated MnFe2O4 nanoparticles: effects of carbon on structure, magnetic properties and Cr(VI) removal efficiency

In this work, the influences of carbon on structure, magnetic properties and Cr(VI) absorption efficiency of carbon-encapsulated MnFe2O4 nanoparticles (MFO/C NPs) are studied. SEM images indicate that the fabricated MnFe2O4 nanoparticles (MFO NPs) are enveloped by carbon layers, forming encapsulating structure. By the BET analysis, it is demonstrated that the average specific surface area of MFO/C samples is higher than that MFO sample. From FTIR and XPS spectra, the presence of carbon-coated MnFe2O4 nanoparticles is confirmed. It is found that the Cr(VI) absorption efficiency of the MFO/C NPs first increases to reach the maximum value at 5% C concentration, and then decreases with the further increment of C concentration. The maximum absorption efficiency and capacity of 90.1% and 73.26 mg/g are obtained, respectively. Finally, a removal mechanism for the removal of Cr(VI) is proposed. The obtained results demonstrate that the carbon-encapsulated MnFe2O4 NPs is a promising candidate as an advanced absorbent for the removal of Cr(VI) from wastewater.

Fabrication, Structure, and Magnetic Properties of Pure-Phase BiFeO₃ and MnFe₂O₄ Nanoparticles and their Nanocomposites

We fabricated pure-phase BiFeO₃ (BFO) and MnFe₂O₄ (MFO) nanoparticles as well as their nanocomposites (BMFO), and then we studied their structures and magnetic properties. Pristine BFO nanoparticles of 93.3 nm average diameter were successfully synthesized using the sol-gel method by varying the solvent condition and the precursor amount. Pristine MFO nanoparticles with a mean diameter of 70.5 nm were synthesized using the co-precipitation method entailing the optimization of the preheating and aging steps. The fabricated MFO nanoparticles showed mostly nanospheres with few nanocubes. The nanocomposite samples of 50 % MFO and 50 % BFO were fabricated through grinding and pelletization, followed by sintering under an inert atmosphere. The crystal structures of the pristine materials in the nanocomposites were well preserved. The magnetization values (Ms) of the BFO, MFO, and BMFO were 4.9, 52, and 33 emu/g, respectively. This latter Ms value was significantly higher than that of BFO, owing to the coexistence of FeSUP2+/SUP and FeSUP3+/SUP in its BFO phase and the incorporation of magnetic MFO. Two synthesis methods and material properties including the structural, morphological, magnetic, and oxidation states of the BFO-MFO nanocomposites were studied in order to achieve a high Ms value of 33 emu/g, which is higher than the bulk values of previously reported BFOMFO composite samples.

57Fe Mossbauer spectroscopy investigation of NiFe2O4 and MnFe2O4 ferrite nanoparticles prepared by thermal treatment method

In this investigation, we have used the thermal treatment method for the preparation of nickel and manganese ferrite nanoparticles. All the samples were calcined at different temperatures from 420 to 570 °C. The results of XRD demonstrated the variation of average nanocrystallite size as a function of calcination temperature. Mossbauer spectra of calcined NiFe2O4 nanoparticles at 570 °C exhibit two sextets, indicating the samples are ferromagnetic, while calcined MnFe2O4 nanoparticles at 420 °C reveal simultaneous presence of two paramagnetic doublets with a central magnetic sextet. The Mossbauer spectroscopy is also applied here for investigating the magnetic hyperfine characteristics and cation distribution of the above-mentioned ferrite nanoparticles. Mossbauer results demonstrate that higher calcination temperature assistances M2+ ions enter into the octahedral sites, while simultaneously Fe3+ ions transfer from the octahedral (B) sites to the tetrahedral (A) sites. As the results indicate, magnetic properties of the samples can be attributed to the hyperfine parameters such as hyperfine field and cation distribution. The results of Mossbauer showed the change in hyperfine parameters along with changing temperature and nanocrystallite size.

Manganese ferrite dispersed over graphene sand composite for methylene blue photocatalytic degradation

Abstract Magnetic materials can be considered as promising catalysts for the degradation of various organic pollutants in wastewater treatment as they can be easily separated with visible light response. The purpose of this research was to develop a highly efficient photocatalyst in decomposing methylene blue (MB) was synthesized using MnFe2O4 nanoparticles supported on graphene sand composite (MnFe2O4-GSC), resulting in an easily, magnetically separable and recyclable photocatalyst. MnFe2O4-GSC was prepared by a solvothermal methodology using commercial sand, graphene oxide (GO) and metal ions (Fe3+ and Mn2+) as precursor materials. The photocatalyst was characterized by scanning electron microscopy, X-ray diffraction, differential reflectance spectroscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy and zeta potential analysis. The results indicated that MnFe2O4 had a spherical shape with uniform size of about 200 nm were successfully loaded and dispersed on the graphene nanosheets and on the sand’s surface. The photocatalytic performance of MnFe2O4-GSC for MB degradation under visible light irradiation was investigated with different reaction conditions, H2O2 concentration, catalyst dosage and pH. The use of the MnFe2O4-GSC as a heterogeneous photocatalyst achieved 100 % degradation of 10 mg L−1 of MB solution at natural pH (pH 7.65) in the presence of 5 mL of H2O2 and 180 min of contact time. In cyclic photodegradation experiments, the performance of MnFe2O4-GSC was stable and practically unchanged regarding its efficiency after five runs. Thus, this research provided a promising strategy for designing efficient and magnetically recyclable photocatalysts for decontamination of dye wastewater under visible light irradiation.

Constructing magnetic separable BiOBr/MnFe2O4 as efficient Z-scheme nanocomposite for visible light-driven degradation of palm oil mill effluent and inactivation of bacteria

Z-scheme BiOBr/MnFe2O4 nanocomposite was successfully prepared by a surfactant-free hydrothermal method. A series of characterizations revealed that the MnFe2O4 nanoparticles were intimately decorated on the BiOBr nanosheets. The as-prepared BiOBr/MnFe2O4 displayed lower charge recombination and higher hydroxyl radical formation rates compared to BiOBr and MnFe2O4. Visible light photocatalytic experimental results showed that the BiOBr/MnFe2O4 possessed excellent performances towards the palm oil mill effluent degradation and Escherichia coli inactivation. The high photoactivity of BiOBr/MnFe2O4 was attributed to the successful establishment of Z-scheme heterojunction between BiOBr and MnFe2O4. Moreover, the BiOBr/MnFe2O4 can easily be recovered using an external magnet and exhibited good repeatability of photoactivity.

Magnetic hyperthermia application of MnFe2O4 nanostructures processed through solvents with the varying boiling point

This article reports the synthesis of MnFe2O4 nanoparticles (NPs) by thermal decomposition method in different solvents such as diphenyl ether, benzyl ether and 1-octadecene with varying boiling point (bp). The physical and chemical properties of all the NPs were systematically studied. The NPs prepared using benzyl ether as solvent formed in cubic shape whereas spherical particles are formed in diphenyl ether and 1-octadecene. The solvent plays a significant role in the reaction and influence the morphology of the NPs. The hydrophobic particles are made hydrophilic by ligand exchange using tetramethyl-ammonium 11-aminoundecanote and the colloidal dispersion of the NPs are used for magnetic induction in varying alternating magnetic field (AMF) of frequency 314 kHz. The specific absorption rates that measure the heat generation in NPs are found to vary with the concentration of the NPs as well as the field strength. The cubic shaped NPs shows comparatively better SAR than the spherical NPs.

Z-scheme heterojunction nanocomposite fabricated by decorating magnetic MnFe2O4 nanoparticles on BiOBr nanosheets for enhanced visible light photocatalytic degradation of 2,4-dichlorophenoxyacetic acid and Rhodamine B

In this study, novel Z-scheme BiOBr/MnFe2O4 nanocomposites were successfully fabricated using a simple and surfactant-free hydrothermal synthetic route. The physicochemical and optical characteristics of the photocatalysts were analyzed by various instruments. The obtained BiOBr/MnFe2O4 nanocomposites significantly accelerated the photodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and Rhodamine B (RhB) when compared with other analyzed photocatalysts under visible light irradiation. Among all samples, the BiOBr/MnFe2O4-10 nanocomposite exhibited the best photocatalytic performance. The improved photoactivity was ascribed to the formation of Z-scheme heterojunction between BiOBr and MnFe2O4, thereby resulting in efficient separation of charge carriers. Photoelectrochemical and photoluminescence analyses were carried out to validate this conclusion. Furthermore, the BiOBr/MnFe2O4 nanocomposite can be easily separated and recycled without significant loss of photoactivity after five consecutive uses. The intermediate products produced during the photodegradation of 2,4-D were also detected. Radical quenching experiments revealed that the hydroxyl radicals played critical roles in the photodegradation reactions. Finally, a possible photocatalytic enhancement mechanism of BiOBr/MnFe2O4 nanocomposites was proposed.

Facile synthesis, antibacterial mechanisms and cytocompatibility of Ag–MnFe2O4 magnetic nanoparticles

Magnetic MnFe2O4 nanoparticles containing 0, 1 and 3 at.% silver, respectively were synthesized by one-pot sol-gel method for antibacterial applications in biomedical fields. Material characterizations indicate that MnFe2O4 begins crystallization at 134 °C and oxidation at 450 °C, the grain size and agglomeration degree increase with the silver content and silver exists as metallic state for the particles. The saturation magnetization decreases with the sintering temperature and slightly increases with the silver content, with the maximum of 50.0 emu/g obtained. Antibacterial tests by plate counting and PI-Hoechst 33342 staining suggest that the antibacterial activity of Ag–MnFe2O4 nanoparticles is silver content-dependent. Silver ions concentration measurement, β-galactosidase activity assay and transmission electron microscopic observation show that the antibacterial activity is dominated by the actions of the released silver ions, rather than the membrane cell impairment or reactive oxygen species-induced oxidative stress mechanism. MC3T3-E1 cell test demonstrates the best cytocompatibility of the nanoparticles with 3 at.% silver, which is likely related to the reduced cell endocytosis of the aggregated particles. The combination of magnetism, antibacterial activity and biocompatibility would make Ag–MnFe2O4 nanoparticles a potential multi-functional material in various biomedical applications.

Immunologically modified MnFe2O4 nanoparticles to synergize photothermal therapy and immunotherapy for cancer treatment

Immunotherapy has been a promising candidate for cancer treatment. The combination of photothermal therapy (PTT) and immunotherapy have shown to cause tumor ablation and induce host immune response. However, this strategy is often hampered by a limited immune response and undesirable immunosuppression. In this work, we developed an immunologically modified nanoplatform, using ovalbumin (OVA)-coated PEGylated MnFe2O4 nanoparticles (NPs) loaded with R837 immunoadjuvant (R837-OVA-PEG-MnFe2O4 NPs) to synergize PTT and immunotherapy for the treatment of breast cancer. The designed R837-OVA-PEG-MnFe2O4 NPs are able to elicit significant immune responses in vitro and in vivo. MnFe2O4 NPs also allowed for a reduction of systemic immunosuppression through downregulation of M2-associated cytokines. More importantly, the R837-OVA-PEG-MnFe2O4 NPs under laser irradiation effectively inhibited tumor growth and prevented lung metastases, leading to a prolonged survival time and improved survival rate. In addition, the designed multitasking MnFe2O4 NPs showed as a desirable contrast agent for magnetic resonance (MR) imaging to diagnose orthotopic breast tumor in vivo. Our work provides a novel strategy for combined PTT and improved immunotherapy in the treatment of breast and other metastatic cancers.

Synergetic Effect of Calcium Doping on Catalytic Activity of Manganese Ferrite: DFT Study and Oxidation of Hydrocarbon

Manganese ferrite (MnFe2O4) and calcium-doped manganese ferrite (Ca-MnFe2O4) were synthesized, characterized, and tested for oxidation of hydrocarbons (CH) in a self-designed gas blow rotating (GBR) reactor. The uniformly sized and thermally stable MnFe2O4 nanoparticles (molar ratio, 1/284.5) showed a reasonable catalytic activity (productivity: 366.17 mmolg−1h−1) with 60% selectivity at 80 °C, which was further enhanced by calcium doping (productivity: 379.38 mmolg−1h−1). The suspicious behavior of Ca-MnFe2O4 was disclosed experimentally and theoretically as well.

Efficient adsorption of Hg(II) from aqueous solution by N, S co-doped MnFe2O4@C magnetic nanoparticles.

N, S co-doped MnFe2O4@C magnetic nanoparticles were successfully synthesized by a simple method involving the preparation of MnFe2O4 nanoparticles and subsequent pyrolysis treatment. The physical and chemical properties of MnFe2O4, MnFe2O4@C and MnFe2O4@C-NS nanoparticles were characterized by X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), N2 adsorption-desorption and the pH at the point of zero charge. Their performances in the adsorption of Hg(II) from water were investigated. The adsorption process followed pseudo-second-order kinetics and the experimental data of equilibrium isotherms fitted well with the Langmuir model. MnFe2O4@C-NS showed the highest adsorption capacity of 108.56 mg/g, increasing more than 1.7 times compared to MnFe2O4. The enhanced adsorption performance was attributed to the larger specific surface area as well as the complexation of N and S ligands on the surface. The thermodynamic parameters of ΔH°, ΔS° and ΔG° at 30 °C were -24.39 kJ/mol, -0.046 kJ/mol K and -10.45 kJ/mol, respectively, which indicated that the adsorption of Hg(II) on MnFe2O4@C-NS was exothermic and spontaneous in nature. Moreover, MnFe2O4@C-NS showed superior selectivity towards Hg(II) compared with other metal ions generally present in mercury-containing industrial wastewater.

MnFe2O4/1-Butyl-3-methylimidazolium hexafluorophosphate modified carbon paste electrode: an amplified food sensor for determination of gallic acid in the presence of ferulic acid as two phenolic antioxidants

A MnFe2O4 nanoparticle/1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6) was incorporated into carbon paste electrode (MnFe2O4/BMIM-PF6/CPE) and used as food electrochemical sensor for the study of the electrochemical determination of gallic acid in the presence of ferulic acid for the first time. The structure and morphology of MnFe2O4 nanoparticle was investigated by TEM methods. Meanwhile, the electrochemical performance of the MnFe2O4/BMIM-PF6/CPE towards gallic acid and ferulic acid determination was demonstrated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The MnFe2O4/BMIM-PF6/CPE exhibited a wide linearity of 0.005–220.0 µM for gallic acid and 0.3–250 µM for ferulic acid with detection limits of 1.0 nM and 0.1 µM, respectively. Furthermore, the ability of MnFe2O4/BMIM-PF6/CPE was tested for the determination of gallic acid and ferulic acid in food products.

Spinel MnFe2O4 nanoparticles (MFO-NPs) for CO2 cyclic decomposition prepared from ferromanganese ores

Ferromanganese ores with high contents of Mn and Fe are abundant worldwide. In this study, spinel-type MnFe2O4 nanoparticles (MFO-NPs) were first synthesized via a novel solid-state reaction process followed by ball-milling, magnetic separation, and nano-grinding. The synthetic MFO-NPs presented a stable spinel structure, fine granularity, and large specific surface; these characteristics highlight their potential in the preparation of thermochemical catalysts. We additionally conducted H2 reduction (HR) and CO2 decomposition reaction (CDR) cyclic tests to investigate the catalytic performance of MFO-NPs. The MFO-NPs showed excellent recyclability and thermal stability during CO2 decomposition; moreover, oxygen-defect MFO-NPs were able to completely decompose CO2 into carbon quantum dots. The mechanism of CO2 decomposition on the MFO-NPs’ surfaces was analysed in detail by XRD, SEM, TEM, TG, Raman, XPS.

Hydrothermal synthesis and photo-Fenton degradation of magnetic MnFe2O4/rGO nanocomposites

Magnetic recoverable MnFe2O4/rGO nanocomposites were synthesized via a facile one-pot hydrothermal method. The microstructure, morphology, optical and magnetic property were characterized by X-ray diffraction, high-resolution transmission electron microscope, ultraviolet–visible spectroscopy, N2 adsorption–desorption technique, photoluminescence spectroscopy and vibrating sample magnetometer. The photo-Fenton degradation activity of the MnFe2O4/rGO composites was investigated using the methylene blue (MB) in aqueous solution under the simulated sunlight. The results show that MnFe2O4 nanoparticles with cubic spinel structure were loaded on the surface of rGO, possessing irregular ellipsoid with uniform particle size and good dispersion. The band gap of MnFe2O4/rGO is narrower than that of pure MnFe2O4 and exhibits redshift. The weak luminescence of MnFe2O4/rGO nanocomposites indicates the efficient separation of photoexcited electron/hole pairs. MnFe2O4/rGO nanocomposites display superior photo-Fenton degradation efficiency of MB, exhibit obvious room temperature ferromagnetism and can be readily recovered by external magnetic field. MnFe2O4/rGO nanocomposites exhibit the best degradation efficiency under the condition of pH 9, 0.5 mL H2O2 and 0.06 g mass fraction in photo-Fenton degradation of MB dye. The radical scavenger tests demonstrate that ·OH, e− and h+ are the main active species and play a decisive role, and rGO plays a vital role in synergistic enhancement of photo-Fenton degradation.

MnFe2O4/ZrO2 nanocomposite as an efficient magnetically separable photocatalyst with good response to sunlight: preparation, characterization and catalytic mechanism

Magnetically separable novel nano-MnFe2O4/ZrO2 nanocomposite (NC) and MnFe2O4 (MFO) samples were synthesized by an efficient solution combustion methodology. The structure, morphology and optical properties were characterized through powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy and UV–Vis spectroscopy. The photocatalytic activity of MnFe2O4/ZrO2 nanocomposite was analysed for decolourization efficiency of methylene blue (MB) and textile dye wastewater under natural sunlight irradiation. The results demonstrated that the decolourization response of the MnFe2O4/ZrO2 nanocomposite was 95% for MB and 59% for textile dye wastewater in 90 min. The photocatalytic performance of MnFe2O4/ZrO2 was almost 1.4 times as high as pure MnFe2O4 was ascribed to the synergic effect and interfacial interaction across MnFe2O4 nanoparticle (NP) and ZrO2 that leads to separation of electron–hole pairs efficiently and broadened light absorption of the composite (2.42 eV) compared to MnFe2O4 (2.15 eV). The effective optimized parameters such as solution pH of 7, nanocomposite dosage of 60 mg and initial dye concentration of 20 ppm were studied on photocatalytic performance for the removal of MB dye. The magnetically separable MnFe2O4/ZrO2 nanocomposite proved to be highly active and a stable catalyst in five successive photodecolourization cycles for an aqueous solution of MB dye under sunlight irradiation. Furthermore, the possible sunlight photocatalytic mechanism of the MnFe2O4/ZrO2 nanocomposite was proposed. Due to its enhancement in photocatalytic activity, this NC has great potential towards the environmental remediation for practical photocatalytic application towards wastewater treatment.