Microwave assisted hydrothermally synthesized cobalt doped zinc ferrites nanoparticles for the degradation of organic dyes and antimicrobial applications

Rational Design and Synthesis of Fe-Doped Co-Based Coordination Polymer Composite Photocatalysts for the Degradation of Norfloxacin and Ciprofloxacin

The solar light-responsive Fe-doped Co-based coordination polymer (Fe@Co-CP) photocatalyst was synthesized under mild conditions. [Co(4-padpe)(1,3-BDC)]n (Co-CP) was first constructed using mixed ligands through the hydrothermal method. Then, Fe was introduced into the Co-CP framework to achieve the enhanced photocatalytic activity. The optimal Fe@Co-CP-2 exhibited excellent catalytic degradation performance for norfloxacin and ciprofloxacin under sunlight irradiation without auxiliary oxidants, and the degradation rates were 91.25 and 92.66% in 120 min. These excellent photocatalytic properties were ascribed to the generation of the Fe-O bond, which not only enhanced the light absorption intensity but also accelerated the separation efficiency of electrons and holes, and hence significantly improved the photocatalytic property of the composites. Meanwhile, Fe@Co-CP-2 displayed excellent stability and reusability. In addition, the degradation pathways and intermediates of antibiotic molecules were effectively analyzed. The free radical scavenging experiment and ESR results confirmed that •OH, •O2-, and h+ active species were involved in the catalytic degradation reaction; the corresponding mechanisms were deeply investigated. This study provides a fresh approach for constructing Fe-doped Co-CP-based composite materials as photocatalysts for degradation of antibiotic contaminants.

Tuning the Magnetic Behavior of Zinc Ferrite via Cobalt Substitution: A Structural Analysis

Cobalt-doped zinc ferrite is a contemporary material with significant structural and magnetic characteristics. Our study explores the magnetic properties of cobalt-substituted zinc ferrite (ZnxCo1-xFe2O4), synthesized via a simple sol-gel method. By varying the cobalt ratio from 0 to 0.5, we found that zinc substitution impacts both the magnetization and lattice parameters. FTIR analysis suggested the presence of functional groups, particularly depicting an M-O stretching band, within octahedral and tetrahedral clusters. X-ray diffraction analysis confirmed the phase purity and cubic structure. The synthesized materials exhibited an average particle size of 24-75 nm. Scanning electron microscopy revealed the morphological properties, confirming the formation of truncated octahedral particles. In order to determine the stability, mass loss (%), and thermal behavior, a thermal analysis (thermogravimetric analysis (TGA)/differential thermal analysis (DTA)) was performed. The magnetic properties of the synthesized ferrites were confirmed via a vibrating sample magnetometer (VSM). Finally, the highest saturated magnetization and lowest coercivity values were observed with higher concentrations of the cobalt dopant substituting zinc. The synthesized nanomaterials have good stability as compared to other such materials and can be used for magnetization in the near future.

Architecture of visible-light induced Z-scheme MoS2/g-C3N4/ZnO ternary photocatalysts for malachite green dye degradation

The synthesis of bilayer heterojunctions has received considerable attention recently. Fabrication of novel bilayer composites is of significant interest to improve their photocatalytic efficiency. In this study, molybdenum disulfide (MoS₂), a layered dichalcogenide material exhibiting unique properties, in combination with graphitic carbon nitride (g-C₃N₄), a carbon-based layered material, was fabricated with small amounts of zinc oxide (ZnO). Three composites, MoS₂/g-C₃N₄, MoS₂/ZnO, and MoS₂/g-C₃N₄/ZnO were prepared via a simple exfoliation method and characterized by various physicochemical methods. The Z-scheme charge transfer mechanism in the prepared ternary composite improves efficiency by inhibiting the recombination rate of electron-hole pairs. It has shown excellent performance in degrading a major water contaminant, malachite green (MG) dye, under visible light irradiation.

Microwave-Enhanced Crystalline Properties of Zinc Ferrite Nanoparticles

Two series of ZnFe₂O₄ mixed cubic spinel nanoparticles were prepared by a coprecipitation method, where a solution of Fe³⁺ and Zn²⁺ was alkalised by a solution of NaOH. While the first series was prepared by a careful mixing of the two solutions, the microwave radiation was used to enhance the reaction in the other series of samples. The effect of the microwave heating on the properties of the prepared particles is investigated. X-ray powder diffraction (XRD), ⁵⁷Fe Mössbauer spectroscopy and magnetometry were employed to prove the cubic structure and superparamagnetic behavior of the samples. The particle size in the range of nanometers was investigated by a transmission electron microscopy (TEM), and the N₂ adsorption measurements were used to determine the BET area of the samples. The stoichiometry and the chemical purity were proven by energy dispersive spectroscopy (EDS). Additionally, the inversion factor was determined using the low temperature Mössbauer spectra in the external magnetic field. The microwave heating had a significant effect on the mean coherent length. On the other hand, it had a lesser influence on the size and BET surface area of the prepared nanoparticles.