Effect of calcination temperature for capability of MFe 2 O 4 (M = Co, Ni and Zn) ferrite spinel for adsorption of bromophenol red

Crystal Plane Impact of ZnFe2O4-Ag Nanoparticles Influencing Photocatalytical and Antibacterial Properties: Experimental and Theoretical Studies

This paper describes the crystal interphase impact of ZnFe₂O₄-Ag in the photodegradation of Rhodamine B. Prepared ZnFe₂O₄ nanoparticles (NPs) were deposited with Ag NPs to offer ZnFe₂O₄-Ag (0-2.5%). An X-ray diffraction peak corresponding to the Ag NPs was detected if the particle content reached about 2.0%, observing multiple crystalline interphases in HR-TEM. Magnetic saturation (Ms) was increased ∼160% times for ZnFe₂O₄-Ag (7.25 to 18.71 emu/g) and ZnFe₂O₄ (9.62 to 25.09 emu/g) if the temperature is lowered from 298 to 5.0 K; while for Fe₃O₄ (91.09 to 96.19 emu/g), the Ms increment was just about 5.6%. After analyzing the DFT-Density of State, a decrease of bandgap energy for ZnFe₂O₄-Ag₆ from the influence of the size of Ag cluster was seen. Quantum yield (Φ) was 0.60 for ZnFe₂O₄, 0.25 for ZnFe₂O₄-Ag (1.0%), 0.70 for ZnFe₂O₄-Ag (1.5%), 0.66 for ZnFe₂O₄-Ag (2.0%), and 0.66 for ZnFe₂O₄-Ag (2.5%), showing that the disposition of Ag NPs (1.5-2.5%) increases the Φ to >0.60. The samples were used to photo-oxidize RhB under visible light assisted by photopowered Langmuir adsorption. The degradation follows first-order kinetics (k = 5.5 × 10^-3 min^-1), resulting in a greater k = 2.0 × 10^-3 min^-1 for ZnFe₂O₄-Ag than for ZnFe₂O₄ (or Fe₃O₄, k = 1.1 × 10^-3 min^-1). DFT-total energy was used to analyze the intermediates formed from the RhB oxidation. Finally, the ZnFe₂O₄-Ag exhibits good antibacterial behavior because of the presence of Zn and the Ag components.

Structural and Magnetoelectrical Properties of MFe2O4 (M = Co, Ni, Cu, Mg, and Zn) Ferrospinels Synthesized via an Egg-White Biotemplate

Nanocrystalline metal ferrites (MFe₂O₄, M = Co, Ni, Cu, Mg, and Zn) were successfully synthesized via autocombustion synthesis using egg white. X-ray diffraction (XRD) measurements revealed the crystallization of the entire ferrites either in the tetragonal structure, such as in the case of CuFe₂O₄, or cubic spinels such as in other studied ferrites. The Fourier transform infrared spectral study revealed the characteristic vibration bands of ferrites. Compared to other synthesis methods, the observed variation in the obtained structural parameters could be due to the different cation distribution of the prepared ferrites. In agreement with XRD measurements, the transmission electron microscopy images showed agglomerated particles with cubic morphology for all ferrites. On the other hand, CuFe₂O₄ showed tetragonal morphology. The magnetization values were found to vary with the type of the metal ion, and CoFe₂O₄ showed the highest one (42.8 emu/g). Generally, the lower magnetization values obtained than those reported in the literature for all studied ferrites could be attributed to the smaller particle sizes or the cation redistribution. The obtained coercivity values are observed to be higher than their related values in the literature, exhibiting the impact of the present synthesis route. Ac-conductivity as a function of temperature and frequency indicated semiconducting properties with the observed change in the conduction mechanism by increasing the temperature. The obtained low dielectric constant values could suggest using the entire ferrites in high-frequency applications such as microwave devices.

Removal of Cu (II) by calcinated electroplating sludge

Electroplating sludge consists of various heavy metal oxides, which may be utilized as adsorbent to remove Cu (II) present in aqueous environment. This study evaluated the adsorption performance of calcinated electroplating sludge. The adsorption isotherm based on Langmuir equation proved that calcinated electroplating sludge had a higher adsorption performance than raw electroplating sludge, with maximum adsorption capacity 92 mg/g and 76.34 mg/g, respectively. Findings of the conducted kinetic study revealed that both surface adsorption and intra-particular diffusion were involved during the adsorption process. Moreover, the comparison between the experimental and calculated data of equilibrium adsorption capacity demonstrated that the pseudo second-order kinetic equation fitted well with 38.31 mg/g of calcinated sludge and 33.66 mg/g of raw sludge, approximate to real-world data. Furthermore, adsorption mechanism research demonstrated that while OH group plays a vital role in raw sample, Ca²⁺, in addition to OH group, was involved in ion exchange in calcinated sample.

Facile synthesis and potential application of Ni0.6Zn0.4Fe2O4 and Ni0.6Zn0.2Ce0.2Fe2O4 magnetic nanocubes as a new strategy in sewage treatment

Disinfection using chlorine has paramount importance in the treatment of either drinking water or sewage since it can kill and inhibit all waterborne pathogens, but it may result in carcinogenic substances when interacting with organic matter. An eco-friendly sol-gel process with citrate was used to prepare the nano-cubic activated nickel-zinc ferrite magnetic nanostructures (Ni_0.6Zn_0.4Fe₂O₄ and Ni_0.6Zn_0.2Ce_0.2Fe₂O₄). The activated nanomagnetic samples were characterized using XRD, HR-TEM, HR-SEM, FTIR, and VSM techniques. The structural and magnetic results showed that the nano-cubes magnetic-structures exhibited higher crystalline degrees and an increase in the total magnetization, enabling spinel nano-ferrite to possess potentials for excellent industry various applications. Likewise, the VSM results reveal that Ce₂O₃ had a significant influence on the magnetic behavior such as the coercivity (Hc; 69.226-133.15) saturation and magnetization (Ms; 24.562-52.174). The results revealed that all Magnetic nanoparticles (MNPs) had an outstanding inhibitory effect on microbes tested. The manufactured particles showed a remarkable ability to eliminate pathogenic bacteria in real sewage samples. The results obtained endorsed that the manufactured magnetic nanoparticles (MNPs) are powerful nano-weapons with an excellent anticipated output for the deactivation of pathogenic microbes during sewage treatment, with, nickel-zinc-cerium ferrite being more effective in inhibiting microbial growth than nickel-zinc-cerium ferrite.

Equilibrium and kinetic studies on methylene blue adsorption by simple polyol assisted wet hydroxyl route of NiFe2O4nanoparticles

A novel approach has been adopted in the synthesis of nickel ferrite nanoparticles and their adsorption capacity was studied in the effective removal of MB dye from aqueous solution. Nanoparticles have a main advantage of treating large amount of wastewater within a short time and producing less contamination. The synthesized Spinel ferrites show high adsorption capacity, magnetic performance, and an eco-friendly material which effectively removes dyes. In the current work Nickel ferrite nanoparticles have been synthesized by wet hydroxyl chemical route using ethylene glycol as a chelating agent. XRD analysis indicates cubic spinel phase nickel ferrite and the average crystallite size is found to be 56.11 nm. An FTIR spectrum illustrates two intense absorption bands in the range between 1000 and 400 cm ^-1 corresponding to the presence of nickel ferrite. The shape and morphology of Nickel ferrite are examined by SEM analysis. The constituent elements and chemical composition analyzed using EDX spectrum showed that the estimated atomic percentages of O, Fe, and Ni are in good agreement with the theoretical value. VSM analysis clarifies soft ferromagnetic nature at room temperature. The equilibrium time for the removal of MB dye was found to be 180 mins. The capacity of nickel ferrite nanoparticles to adsorb the MB dye was proved from its maximum adsorption capacity of 72 mg g^-1 from Langmuir model. The Equilibrium parameter (R_L) and % error was calculated and found that Langmuir isotherm and Second-order kinetic model gave a good fit to the experimental data.

Mechanochemical Synthesis of CuO/MgAl2O4 and MgFe2O4 Spinels for Vanillin Production from Isoeugenol and Vanillyl Alcohol

CuO/MgAl₂O₄ and CuO/MgFe₂O₄ catalysts were successfully synthesized with the use of spinel supports by a very simple and low-cost mechanochemical method. High-speed ball-milling was used to synthesize these catalyst supports for the first time. Materials were subsequently characterized by using XRD, FESEM, TEM, EDS-Dot mapping, XPS, BET-BJH, and Magnetic Susceptibility to investigate the physical-chemical characteristics of the catalysts. Acidity evaluation results indicated that the catalyst with the Mg-Al spinel support had more acid sites. XRD results showed a successful synthesis of the catalysts with large crystal sizes. Both catalysts were used in isoeugenol oxidation and vanillyl alcohol to vanillin reactions, with the CuO/MgAl₂O₄ showing optimum results. This catalyst provided 67% conversion (74% selectivity) after 2 h and this value improved to 81% (selectivity 100%) with the second reaction after 8 h. The CuO/MgFe₂O₄ catalyst in the first reaction after five hours revealed 53% conversion (47% selectivity) and after eight hours with the second reaction, the conversion value improved to 64% (100% selectivity). In terms of reusability, CuO/MgAl₂O₄ showed better results than the CuO/MgFe₂O₄ catalyst, for both reactions.

Preparation of Attapulgite/CoFe2O4 Magnetic Composites for Efficient Adsorption of Tannic Acid from Aqueous Solution

The use of attapulgite (ATP)-based materials for adsorption of pollutants from water and wastewater has received growing attention. However, recovering ATP-based adsorbents remains a challenge. In this study, a magnetic adsorbent ATP/CoFe₂O₄ with high tannic acid (TA) adsorptive capacity was fabricated via a facile co-precipitation approach and was well characterized. The loaded CoFe₂O₄ particles were embedded into the adsorbent surfaces to allow magnetic separability. For this material, its TA adsorption kinetics, isotherm behavior, and magnetic separation efficiency are reported. The developed magnetic composites had rapid sorption kinetics of 3 h, high sorption capacity of 109.36 mg/g, and good magnetic separation efficiency of 80%. The used ATP/CoFe₂O₄ was successfully regenerated by NaOH and reused five times without a substantial reduction in TA removal and magnetic performance. Intermolecular hydrogen bonding formation and surface complexation were identified as the sorption mechanisms of TA by ATP/CoFe₂O₄.

A study of biochemical route on construction of waste battery ferrite applying for nickel removal

Mn-Zn ferrite (Mn_1 - xZn_xFe₂O₄, x = 0.2, 0.4, 0.6, and 0.8) nanomaterials were prepared by bioleaching and hydrothermal synthesis from waste Zn-Mn batteries. The materials were characterized by XRD, SEM, BET, VSM, CEC, and isoelectric point. It turned out when x = 0.4, synthesized Mn-Zn ferrite had best performance which was nanoferrite crystal structure with a specific surface area that reached 37.77 m²/g, the saturation magnetization was 62.85 emu/g, and isoelectric point and the CEC value were 7.33 and 43.51 mmol/100 g, respectively. In addition, the adsorption characteristics on Ni²⁺ were explored. The results of experiment suggested that data was more in line with the Freundlich model compared with Langmuir and Dubinin-Radushkevich isotherm models. Kinetics studies showed that pseudo-second-order kinetics was more suitable for describing the Ni²⁺ adsorption process where the maximum theoretical adsorption quantity was 52.99 mg/g. Thermodynamic parameters indicated the adsorption process can be spontaneous as an endothermic reaction, and warming was advantageous to adsorption. Besides, the adsorbent could be reused for six cycles with high removal efficiency. The magnetic and adsorptive properties of the adsorbent were promising, which had a high application value. Graphical abstract Fabrication process of nanometer ferrite by biological technology and hydrothermal synthesis for removal of Ni2.